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Search drilling fluid chemistry: 4.3.3 Solids
...SPE 65000 High-Density Invert-Emulsion System with Very Low Solids Content to Drill ERD and HPHT Wells 11 Table n. 4 - Tests with Cesium Formate Formulation: g g Sy...300 200 100 6 3 G 0 /G 10 AV PV YP ES agent agent Synt. Paraffin A Ilmenite WA02 96 52 37 21 4 3 3/5 48 44 8 275 Synt. Paraffin B Ilmenite WA02 74 40 28 16 3.5 3 3/4 37 34 6 270 Measurements at 120 ...
...SPE 65000 High-Density Invert-Emulsion System with Very Low Solids Content to Drill ERD and HPHT Wells 13 Table n. 9 - Typical Properties of Two Different Weighting ...ighting 600 300 200 100 6 3 G 0 G 10 AV PV YP ES agent agent 2137/3 WA02 Ilmenite 96 52 37 21 4 3 3 5 48 44 8 275 2137/3 WA02 Barite 112 59 41 23 4 4 4 5 56 53 6 1000 Measurements at 120 F AHR 16h a...
...SPE 65000 High-Density Invert-Emulsion System with Very Low Solids Content to Drill ERD and HPHT Wells Luigi F. Nicora, SPE, Pierangelo Pirovano, SPE, Lamberti SpA, ...s the laboratory development of a new Low density (ECD) and high surge and swab pressures. To build Solids Oil Based Mud System (OBMS) with a very high mud with such high densities, the concentration of wei...y 35% v/v. Together as solid free oil based mud with very low viscosity at densities with the drill solids and the organophilic clay, the total amount up to 1.52 SG, especially suggested for Extended Reach ...
Abstract The paper describes the laboratory development of a new Low Solids Oil Based Mud System (OBMS) with a very high specific gravity (2.04 SG; 17 ppg) for high-temperature and high-pressure applications. The system can also be applicable as solid free oil based mud with very low viscosity at densities up to 1.52 SG, especially suggested for Extended Reach Drilling Wells. The main goals of the new system are:Optimization of fluid rheology by reduction of the solids contents in the mud. Temperature and system stability at 170°C. The objectives have been pursued in the following ways:by using a very heavy brine as the internal phase; by decreasing the oil / brine ratio; by using a weighting agent with higher density than barite. In this way, the amount of weighting solids which needs to be added can be drastically reduced to even below 22% v/v for a 2.04 SG mud, compared to 35% v/v as in traditional oil based muds. Also the PV values have been reduced from typically round 60 cP to even below 25 cP. The addition of new components to the system has lead to the need of a new emulsifier package, which has been optimized with the development of a primary emulsifier and a wetting agent based on innovative chemistries. Introduction Saga Petroleum discovered in 1997 a new high temperature high pressure (HTHP) field offshore Norway, the Kristin field. A total of three exploration wells have been drilled on the Kristin structure. The temperature in the reservoir is 175°C and the pressure 930 bar, requiring the use of drilling fluids with high temperature stability and high density (2.04 kg/l). The drilling of these wells has identified the need of developing a drilling fluid system with better rheological properties and improved temperature stability. Conventional oil based mud has been used in exploration drilling. In vertical wells the mud has behaved satisfactorily but, when drilling inclined hole, a lot of mud related problems occurred such as barite settling, high equivalent circulating density (ECD) and high surge and swab pressures. To build mud with such high densities, the concentration of weight material needs to be very high. In the wells drilled in the Kristin field the amount of barite was approximately 35% v/v. Together with the drill solids and the organophilic clay, the total amount of solids in the mud was reaching almost 40% v/v. This very high solids content makes it very difficult to achieve a good rheological profile of the mud. To develop the Kristin field for production several extended reach drilling (ERD) wells need to be drilled. Drilling of these wells cannot be done with this type of mud because of the high ECD, caused by the high rheology of the mud, which might fracture the formation and cause lost circulation problems. The development of a new oil based mud system, which gives far lower ECDs, is therefore essential to be able to drill the necessary wells. Invert emulsion fluids consist of a salt water solution dispersed into a continuous hydrophobic phase. This emulsion is stabilized by emulsifiers. The salt water phase has traditionally been a CaCl2-brine, often with lime added for alkalinity. The oil / water ratio is traditionally in the range of 65/45 - 85/15. The concentration of solids in the mud will often dictate the oil / water ratio. In solids laden muds the oil ratio must be high, to keep the solids oil wet and dispersed.
- Europe > Norway > Norwegian Sea (0.65)
- North America > United States > Texas (0.46)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.68)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Tofte Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Ile Formation (0.99)
- Europe > Norway > Norwegian Sea > Halten Terrace > PL 199 > Block 6506/11 > Kristin Field > Garn Formation (0.99)
- (9 more...)
...on and formulation (chemistry, properties) 1.11.3 Drilling fluid management and disposal 1.11.4 Solids control 1.11.5 Drilling hydraulics 1.11.6 HPHT hydraulics 1.11.7 Cuttings transport 1.11.8 ...nt 2.3.6 Tubular optimization 2.3.7 Downhole tools and equipment 2.4 Sand control 2.4.1 Sand/solids control 2.4.4 Screen selection 2.4.5 Gravel pack design & evaluation 2.4.6 Frac and pack 2... Downhole intervention and remediation (including wireline and coiled tubing) 3.2.3 Produced sand/solids management and control 3.2.4 Produced water management and control 3.2.5 Downhole fluids separa...
- Information Technology > Artificial Intelligence (1.00)
- Information Technology > Communications > Networks (0.69)
- Information Technology > Communications > Collaboration (0.50)
- Information Technology > Architecture > Real Time Systems (0.47)
...od 2 is about 12 - 17 minutes, and the speed of dosing is between 1.3 - 1.6 (average 1.39) MT/hr or 4.3 - ...3.4 (average 3.6) m 3 /hr. For comparison, the dosing capacity of the disk batcher, mud preparati...o becomes "unpumpable". This observation on the solid phase characteristic is evident regardless of solids type, i.e. cement, chalk and hollow glass spheres. In other words - at the same volume content of t...
...w glass spheres into drilling mud is similar to that of weighting materials: the phase of dispersed solids is held in thixotropic fluids in the state of equilibrium at a particular gel strength value. Stand...ttings from the fluids. To ensure acceptable rheological characteristics, the volume content of the solids phase in suspensions (not depending on material) should not exceed 40%. It is important to mention ...y of 0.75-0.87 g/cm 3 . It is important to note that at this density, the volume content of the solids' phase in the fluid will be within 25-40% range consequently providing easy control of the mud's rh...
... - space requirement for storage at platform or jack-up and supply vessel; - loss of spheres at the solids control equipment; 3 methods were evaluated to optimize the efficiency and safety aspects of blendi...
Copyright 2010, SPE/IADC Managed Pressure Drilling and Underbalanced Operations Conference and Exhibition This paper was prepared for presentation at the 2010 SPE/IADC Managed Pressure Drilling and Underbalanced Operations Conference and Exhibition held in Kuala Lumpur, Malaysia, 24-25, February 2010. This paper was selected for presentation by an SPE/IADC program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers or the International Association of Drilling Contractors and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers or the International Association of Drilling Contractors, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers or the International Association of Drilling Contractors is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied.
- Asia > Vietnam > South China Sea (1.00)
- North America > United States > Mississippi > Perry County (0.41)
- North America > United States > Gulf of Mexico > Western GOM (0.41)
- North America > United States > Gulf of Mexico > Central GOM (0.41)
- Asia > Vietnam > South China Sea > Cuu Long Basin > Block 9-2 (0.99)
- Asia > Vietnam > South China Sea > Cuu Long Basin > Block 09-1 > Bach Ho Field (0.99)
- Europe > Norway > North Sea > Central North Sea > Utsira High > Greater Luno Area > Basement (0.98)
...12 IPTC-13238 Low-tox MOBM Low-tox MOBM Optimal treatment 4 4 3 3 2 2 1 1 0 0 0 0 1 1 2 2 3 3 IPL-1 (%) IPL-1 (%) Low-tox MOBM Low-tox MOBM 4 ...4 3 3 2 2 1 1 0 0 0 0 1 1 2 2 3 3 IPL-1 (%) IPL-1 (%) Figure 7--Phases centrifugally separated f...
... used oil-based drilling fluids. The method is based on destabilizing and aggregating the suspended solids and brine droplets through the application of polymers and surfactants in a controlled mixing devic...e. The aggregated material may then be centrifugally separated using traditional solids-control equipment. This allows recovery of the oil-continuous phase, which may then be recycled int...antiate the efficacy of this solid-liquid separation method. Microscopic analyses of the aggregated solids support a proposed mechanism based on preferential wettability. Background Several aspects of petro...
...mal treatment thermal (distillation) Spent Drilling Fluids Throughout the drilling process drilled solids must be continually removed from the circulating fluid to maintain fluid properties within engineer...size distribution of brine droplets and their state of colloidal stability must also be controlled. Solids control at the level of screens, shakers and even centrifuges necessarily result in the accumulatio...n of fine solids and formation water in used fluids. Settling velocities (v t ) of particles, in normal gravity ...
Abstract A novel approach has been taken to separating, recovering and recycling the oil-continuous phase from used oil-based drilling fluids. The method is based on destabilizing and aggregating the suspended solids and brine droplets through the application of polymers and surfactants in a controlled mixing device. The aggregated material may then be centrifugally separated using traditional solids-control equipment. This allows recovery of the oil-continuous phase, which may then be recycled into another oil-based drilling fluid. Laboratory data and field case studies will be presented that substantiate the efficacy of this solid-liquid separation method. Microscopic analyses of the aggregated solids support a proposed mechanism based on preferential wettability. Background Several aspects of petroleum production rely on solid-liquid-liquid separation of oil-continuous dispersions comprised of discrete aqueous and solid particulate phases. Such mixtures occur as drilling fluids, as produced fluids, at various stages in upgrading feedstock for refineries, and as a variety of waste streams derived from drilling, production and delivery operations. The efficiency and speed of mechanical separation of colloidally dispersed materials is greatly improved by aggregating fine particulates and coalescing liquid droplets as long as their densities are sufficiently different from the continuous phase. Improving solid-liquid-liquid separation in petroleum applications can have great economic and environmental benefits. This paper discusses a chemical and mechanical treatment scheme employing surfactants and inverse polymeric emulsions to concurrently improve particulate flocculation and droplet coalescence, thereby improving solidliquid-liquid separation in a conventional centrifuge. The petroleum industry necessarily produces large quantities of complex mixtures of oil, water and solids either by design, as a consequence of natural resource recovery, or as a byproduct resulting from normal operations. Management of these fluid streams is not only good practice, but it can also make good economic sense, especially if components can be recycled. Drilling fluid management practices involve minimization, recycle/reuse, disposal or some combination of these practices (1). Strategies that minimize or dispose of waste is only one of cost avoidance, whereas strategies that rely on recycle/reuse can produce positive economic as well as environmental benefits. Current practices for disposing oily wastes include:onsite burial (pits, landfills) bioremediation offsite disposal to commercial facilities re-injection thermal treatment Current practices to recycle/reuse oily byproducts include:recycling fluids road spreading reuse of cuttings for construction purposes use of oily cuttings as fuel
- North America > United States (0.46)
- Europe > United Kingdom (0.28)
- Energy > Oil & Gas > Upstream (1.00)
- Water & Waste Management > Water Management > Lifecycle > Treatment (0.56)
... 8 8 28 8 74 10 80 8 6 6 300 revlmin 4 4 16 5 50 6 52 5 3 3 Apparent viscosity. cp 4 4 14 4 37 5 40 4 3 3 Plastic viscosity, cp 4 4 12 3 24 4 28 3 3 3 Yield point, Ibfl100 ft 2 0 0 4 2 26 2 24 2 0 0 1 O...C no control. The mud can also be formulated with potassium chloride. The muds tolerated much more solids than conventional Potassium acetate is preferred for improved shale potassium systems. For example,... contamination with 15% stabilization, ease of disposal, and to avoid logging problems drill solids (grundite shale) gave no increase in yield point associated with high chloride concentrations. Preh...
...provided fluid-loss control at 400 F [204 C] to clay-free saturated-salt laboratory muds and to low-solids, nondispersed field muds contaminated with drill ...solids and sodium and calcium salts. High-temperature/high-pressure (HTHP) filtrate was kept at $ 15 c...ghted ( IS-Ibm/gal [ 2157-kg/m3]) potassium muds treated with the polymer showed heat stability and solids and green-cement tolerance. The polymer was successfully field-tested in two offshore wells where b...
...eased carboxylate of a basic filter cake, increase in viscosity of the filtrate, groups. coating of solids, reaction with clays, and bridging to plug In analysis, two functional groups, vinyl and acrylamide...
Summary. The suitability of a synthetic copolymer for drilling deep, hot wells was demonstrated through laboratory and field testing. The polymer provided fluid-loss control at 400F [204C] to clay-free saturated-salt laboratory muds and to low-solids, nondispersed field muds contaminated with drill solids and sodium and calcium salts. High-temperature/high-pressure (HTHP) filtrate was kept at less than or equal to 15 cm3/30 min after 400F [204C] heat-aging of a 19-lbm/gal [2277-kg/m3) saturated-salt mud. Weighted >18-lbm/gal [ >2157-kg/m3) potassium muds treated with the polymer showed heat stability and solids and green-cement tolerance. The polymer was successfully field-tested in two offshore wells where bottomhole temperatures (BHT's) reached 400F [204C] and salt and calcium chloride flows were encountered. Introduction Drilling deep, hot wells with water-based fluids has been limited by lack of additives that would maintain stable rheologies and fluid-loss properties at elevated temperatures. The problem is accelerated when high chemical contaminants are encountered-e.g., salts of sodium, calcium, and magnesium. The number of wells drilled with BHT's higher than 400F [204C] is relatively small, but it is expected that in conquering the unknown frontiers, the occurrence of deep, hot wells drilled through salt beds and other hostile formations will increase, Mobile Bay, AL, is one of the areas that currently is taxing drilling technology to the limit. This investigation was undertaken with the objective of extending the utility of water-based fluids to depths where temperatures higher than 400F [204C] occur and where formations release deleterious chemical contaminants. A synthetic sulfonated copolymer is discussed that provides the dual functions of rheological stabilization and fluid-loss control under such unfavorable conditions. Considerations for Filtration Control in Drilling Fluids Statistically, the mud bill is a minor fraction of the total cost of drilling a well. The drilling fluid, however, is not a minor factor in successfully making the desired hole in the ground. Success is equated to economics, efficiency, and safety in completing the drilling project. The drilling fluid can be as simple and cheap as field water viscositied by mud-making shales. As the search for hydrocarbons goes deeper into the earth and to the bottom of the ocean, however, the conditions in the well-bore get drastically transformed. Elevated temperature gradients and hostile environments are encountered. The composition and maintenance of the mud system correspondingly becomes complicated. Sustenance of suitable drilling-fluid rheologies and filtration characteristics is necessary to maintain efficiency of the drilling process. Drilling fluids are designed to suit the wellbore conditions-e.g., permeability, chemical composition of the formation. and temperature. The conditions constantly change with depth, dictating continuous monitoring of mud properties. A well-known phenomenon in chemical kinetics is the doubling of speed or rate of a chemical reaction with every 18F [10C] increase in temperature. In water-based drilling-fluid systems, components that are relatively inert to each other under surface conditions become highly reactive as temperature rises. For example, bentonitic clays, commonly used to impart viscosity and filtration-control properties, form stable systems in the presence of large concentrations of hydroxyl ions (most mud systems are highly alkaline). At temperatures higher than 200F [94C], the hydroxyl-ion/clay interaction occurs at rates sufficient to change the rheological behavior of the fluid. During the circulation downhole and back to the surface, the mud picks up contaminants (extraneous materials not present when the fluid was originally formulated). Drill solids, cement, and salts are common contaminants. At low temperatures, the mud may be able to tolerate the contaminants, but at elevated temperatures, remedial measures are often necessary. Rogers categorized high temperature as a mud contaminant. The basic difference between high temperature and the other mud contaminants-e.g., salt, cement, and drill solids-is that temperature cannot be treated out. The drilling fluid must be conditioned to perform in its presence. In water-based drilling fluids, filtration control is a closely monitored mud characteristic. Numerous problems have been associated with excessive invasion of aqueous filtrate into permeable formations. SPEDE P. 209^
... properties of a copolymer deflocculant (CPO) and lignosulfonate drilling grade clays and formation solids treated (LS) were performed to differentiate their behavior. with a copolymer deflocculant (CPO) an...e slurry surface area as a function of pore diameter was calculated. Assuming parallel additive and solids concentration at various j stacking of spheres based on porosity consideration, salinities and t...he resultant charge of polymer-· interparticle distance was calculated using a geometrical treated solids. model. Interparticle distance calculated by this approach compares favorably to theoretical calcul...
...e indicated that their behavior in the osmotic potential, is described as: the. presence of drilled solids and contaminants such as carbon dioxide gas is not well understood. Laboratory (2) and field data ...or fresh water to function depends significantly on the type and amount K 107 cm-1 for seawater of solids in the drilling fluid and its electrolyte d distance between particles em, Dss in this content. pa... reaches a critical concentration, aggregation of dimensionless quantitiy of the surface potential, solids occurs and fluid properties deteriorate. then gamma which is related to how the charge decays Aggre...
...essure.l9 The equation paper, slurry permeability, mean pore diameter, and surface area of hvdrated solids by basic filtration (9) equations.l2,14,18 19,2U Surface area is calculated by assuming parallel s... zeta 1 cp 10-N s/M2 potential has been the subject of much discussion and c Concentration of solids in cake, Kg/M3 theoretical treatment.! Firth and Hunter used a for colloidal slurries, taken to be ...ed data suggests that for highly stable colloidal slurries, correction of C to the concentration of solids in the cake is in In this study, the zeta potential was measured order. on dilute ...
Abstract This paper presents capillary suction time (cst), zeta potential, and rheological properties of drilling grade clays and formation solids treated with a copolymer deflocculant (CPD) and lignosulfonate (LS) in fresh water and various concentrations of seawater. Also, the reaction of calcium with CO2 in the presence of CPD was investigated. To better explain cst values, they were converted to specific resistance to filtration and slurry permeability. From permeability data, average pore diameter was calculated. Assuming parallel stacking of spheres based on porosity consideration, interparticle distance was calculated using a geometrical model. Interparticle distance calculated by this approach compares favorably to theoretical calculations by Van Olphen for sodium montmorillonite as a function of clay concentration. Data from systems investigated was treated by the DLVO theory of colloid stability. Results with CPD and LS show that critical volume fraction or interparticle distance occurs with both systems between 5% and 7% by volume solids for the shale studied. Lower calculated attractive force was observed for solids treated with CPD. Also, rheological and shear strength tests on field muds show that CPD reduces colloidal interactions between particles. Studies in acid gas environment show that while CPD can solubilize calcium, calcium is available to react with CO2 in an alkaline environment to precipitate calcium carbonate. Results also show rheology is not affected by acid gas. Introduction Copolymer deflocculants are increasingly being used as a substitute for and in conjunction with lignosulfonates as rheological control additives in all types of water-based drilling fluids. Because of the inherent stability of these deflocculants over a wide range of conditions, it has become important to better understand how these materials work to extend their application range. Comparative studies between a copolymer deflocculant (CPD) and lignosulfonate (LS) were performed to differentiate their behavior. Since traditional methods of drilling fluid analysis provide an incomplete understanding of clay polymer interactions, fundamental colloidal and surface chemistry methods along with rheological measurements have been used to explain the behavior of polymeric deflocculants. These methods were used to measure slurry surface area as a function of additive and solids concentration at various salinities and the resultant charge of polymer-treated solids. Polyacrylates with 1500 to 5000 molecular weight have been used as rheological control agents in many industries since the 1950's. Evolution of these materials to modified polyacrylates was required in the drilling fluids industry because of harsh chemical environments such as high divalent ion concentration, salinity, and temperatures. The generalized formula for a CPD is shown below. The highly ionic sulfonate group imparts divalent cation and salinity tolerance by preventing charge neutralization of the polymer. Past applications of these materials have been in the area of scale control since they prevent mineral crystallization of calcium carbonate, calcium and barium sulfate.
- North America > United States > Louisiana > Standard Field (0.99)
- North America > United States > Gulf of Mexico > Western GOM > West Gulf Coast Tertiary Basin > High Island (0.98)
... 13.1 20 10 7 4 2 1 4.21 0.37 Settled 13.1 51 30 23 15 4 3 14.23 1.90 0.5 Ibm/bbl xanthan gum 8.7 6 4 3 3 1 1 3.90 0.48 13.5 37 25 20 18 10 8 13.39 2.07 8.7 6 4 4 3 2 2 9.41 2.43 8.7 6 5 4 3 2 2 5.98 0.92 ...25 14 11 10 5 4 8.30 1.21 14.0 25 16 13 11 9 8 10.00 1.62 8.7 33 25 20 16 5 2 18.14 2.80 8.7 10 6 5 4 3 3 7.68 1.34 8.7 3 3 2 2 2 1 1.42 0.09 15.5 46 29 24 17 9 7 14.44 2.47 15.5 143 89 66 41 7 3 27.27 3.1...4 2 1 5.98 0.92 16.0 37 20 14 10 5 6 6.53 0.58 Slight settling 8.7 8 5 4 3 2 1 5.98 0.92 8.7 10 6 5 4 3 3 7.68 1.34 16.7 28 10 7 5 2 1 3.39 0.30 Settled 16.7 29 19 16 13 12 12 10.87 1.95 8.7 7 4 3 2 1 1 3...
... for each spacer are compared, and settling, foaming, and mixing problems are discussed. Because of solids settling in either the slugging pits or surface samples, the spacer formula is sometimes modified o...n location to improve solids suspension. The rheological effects of increasing concentrations of base spacer material, bentonite... with the cement service company. Often the mud possess sufficient suspension properties to prevent solids settling engineer and/or a member of the rig crew is responsible for spacer on surface, but that ei...
...he are not quantitative measurements for compatibility; thus, the results same density, thus adding solids to the spacer, again affecting the are subject to operator interpretation. The mud/spacer compatibi...lations made for turbulent flow rates are based on pure or PAC, were not made unless a problem with solids suspension fluids-i.e., those without any intermixing. If the spacer is not rheologically was exper...
Summary. Rheological data from cementing-spacer fluids are usually based on laboratory-prepared samples of the spacer and used to determine the flow rate required to provide the flow regime necessary for maximum efficiency of the spacer and to estimate the annular friction pressures associated with the spacer. Actual rheological properties are rarely measured on location, and the problems experienced with settling, foaming, and mixing are difficult problems experienced with settling, foaming, and mixing are difficult to simulate in the laboratory. This paper reviews the field data from three commercial spacers mixed at offshore locations and compares them with laboratory data for base spacer materials and weighted spacer mixes. The flow rates required to obtain turbulent and plug flow for each spacer are compared, and settling, foaming, and mixing problems are discussed. Because of solids settling in either the slugging pits or surface samples, the spacer formula is sometimes modified on location to improve solids suspension. The rheological effects of increasing concentrations of base spacer material, bentonite, and polyanionic cellulose (PAC) are discussed with a comparison of the rheological data from these spacers. Introduction Some scientists 1–7 have indicated that maximum mud removal can be obtained through the use of a turbulent-flow spacer. Plug-flow systems have also been used successfully in many field applications. Other scientists have stated that regardless of the flow regime, the best mud removal is obtained by maximizing the flow rate in the well. Turbulent-flow-system design depends on spacer systems that possess sufficient suspension properties to prevent solids settling possess sufficient suspension properties to prevent solids settling on surface, but that either go easily into turbulent flow in the annulus, or at least minimize the friction pressure in the annulus at high pump rates. Because of the critical balance of these parameters, the quality of the base spacer material and of field parameters, the quality of the base spacer material and of field mixing of the spacer must be maintained at a high level. The surface rheology of a plug-flow spacer should be sufficient to suspend the weighting agent, but the ability to retain this viscosity downhole and to minimize annular friction remains a concern. This paper outlines the factors that can lead to variations in spacer rheology-particularly mixing equipment, personnel, and materials quality-and discusses the performance characteristics of the spacer on the cement job. Mixing Equipment More control can be kept over the type of mixing equipment used in spacer mixing for land-based than for offshore operations. The service company will generally provide the pumping equipment, which is normally the same equipment used to mix the spacer and the cement. Also, the spacer dry mix and weighting agent are normally blended at the service company bulk plant and delivered to the location as a complete mix. Offshore rigs lack sufficient space for additional mixing equipment and the required bulk capacity for holding a preblended spacer mixture, so sacks of dry spacer material are delivered with the appropriate mixing instructions for batch mixing in the rig's slugging pit. Barite is supplied by the rig for weighting the spacer to the desired density. These factors limit the amount of quality control possible at offshore locations. Also, mixing equipment and the amounts of materials added to make the spacer are not standard. The lack of standardized mixing equipment causes wide variations in the amount of shear applied to the spacer and in the final spacer rheology from one rig to another. Depending on spacer composition, the sensitivity to the amount of shear and the length of time shear is applied can drastically affect spacer properties. The problem with slugging pits usually is not excessive shear but lack of sufficient shear to yield spacer quickly. The spacer is therefore subjected to a longer low-shear period than in the laboratory. Because spacers are typically mixed m the slugging pit, the cleanliness of the mixing equipment may be questionable. In some situations, removing all the drilling mud from the mixing system can be difficult, and some residual mud may be found in the mixing system when the pumps are turned on to mix the spacer. Unless the amount of mud is excessive, slight contamination should not significantly affect the spacer. The initial rheology, however, can be affected, depending on the degree of contamination. Personnel Personnel The personnel charged with mixing the spacer offshore are usually not associated with the cement service company. Often the mud engineer and/or a member of the rig crew is responsible for spacer mixing but may not be familiar with the spacer or its expected performance in the well. In many instances, the only information the performance in the well. In many instances, the only information the mud engineer has is the amounts of water and spacer to mix. From there, the mud engineer must mix the spacer to the proper initial viscosity, increase the weight to the planned density without any solids settling, and pump the spacer into the well. The cement service company personnel are rarely involved in spacer mixing. They often have limited knowledge of the rig mixing equipment and are required to prepare for the cement job. Because of the differences in mixing equipment used offshore and because untrained personnel usually mix the spacer, the final spacer mixture and its properties are not consistent under field conditions. When the final spacer rheology is critical, additional care must be taken to ensure that the spacer has the properties specified in the plan, which requires that the personnel mixing the spacer know the plan and the actions required to obtain the desired results. Sauer recommended that a member of the cement service company be responsible for mixing the spacers, that spacer rheology be measured after mixing, and that the critical flow rates be recalculated on location. During this project, some spacers were mixed with the guidance of the service company representative, but the results still varied. The differences in final spacer properties appear to result from the inconsistencies of materials and mixing equipment rather personnel. Without the proper controls over spacer properties and a consistent method for obtaining these results, properties and a consistent method for obtaining these results, spacer properties will vary regardless of who mixes the spacer. Materials Quality Control Although quality control of the base spacer material should be checked by the service company, storage on the rig can alter its quality. Exposure to moisture can be detrimental to the spacer quality, and care must be taken to provide either dry, or at least covered, storage areas. Limiting the amount of spacer material in inventory can solve storage problems and can ensure fresh material for each job. Differences in spacer quality can also be related to the mix water available on location. Some polymers used in spacers can be sensitive to pH, salinity, and specific ion concentrations. Some either will not fully yield or can actually crosslink if the water quality is too far from specifications. The volume of water used to mix the spacer is equally important. Slugging pits are not usually calibrated to the accuracy of cement-batch-mixing equipment; thus, the final volume of mix water can vary. Some spacers appear to be much more sensitive to water quantity than others. SPEDE P. 196
...ge. However, small volume discharges of synthetic-based mud (SBM) are permitted (EPA 2007). The SBM solids that accumulate at the end of the well has been estimated to average 75 bbl containing 25% SBM, wit...to discharge to the local sewer and there were additional controls of the amount of total suspended solids, biological oxygen demand and mineral oil and grease (Table 2). Drilling Slop Treatment Drilling sl...ea spray and from the fire system. The fluid contains contamination levels of 1,000 mg/L oil and 1% solids. The appearance will be like an oil film at the surface of the water and small amounts of sediments...
...chieved by applying centrifugal force. Decanting centrifuges can be used to remove course and heavy solids from the fluid. Finer ...solids and oil can be removed using disc stack centrifuges, which are commonly present on the rig as part ...onsistently below the 40 mg/L discharge limit. Chemical Coagulation and Flocculation. Separation of solids, oil and dissolved species can be enhanced by chemical coagulation and/or flocculation. The chemica...
...minated Fluids. Contaminated fluids are considered to be ones containing 1 to 35% oil and up to 10% solids. They could be aqueous in nature like the lightly contaminated fluids but with a higher degree of c...he system may remain water wet, but contain significant quantities of water-wet mud, dispersed oil, solids and emulsifiers. When the drilling fluid itself has become contaminated during displacement to brin...e, pills or spacers, the presence of excess emulsifiers and oil-wet solids in a typical invert emulsions drilling fluid makes it very easy to emulsify large quantities of exc...
Abstract Regulations governing offshore discharge are increasingly stringent and diverse, varying between country, legislative framework and type of discharge. One major waste stream is the slop generated during the drilling operation, which is collected in the rig drain systems or in surface pits. The slops come from multiple sources, vary widely in composition and are therefore challenging to treat to meet the discharge regulations of a global market. Slops are formed when drilling or displacement fluids, wash water from routine cleaning operations or rain water runoff become contaminated with drilling fluid components. The slops are captured, either in surface pits or through the rig drain system and collected in storage tanks. Chemical and physical treatments can be used to treat this stream to minimize the volume and cost of disposal, but due to the complex and varied nature of the slop stream, treatment methods must be tailored. Optimal solutions should treat the stream to recover and recycle any drilling fluid. Water should be separated and treated to meet the discharge criteria. In this way the total volume of waste requiring disposal can be significantly reduced. This paper will present a review of the discharge criteria relating to drilling slop waste, highlighting the variations seen between countries. The paper will discuss how this variability, together with the slop chemical characteristics, impacts optimum treatment methods. Examples will be provided of successful treatments of a variety of slop wastes, where both chemical and physical treatment was successfully applied to meet a range of discharge criteria from oil content to complex organic analysis. Understanding slop treatment and the multitude of discharge regulations that can be applied will permit the optimal solution for slop treatment to be selected to minimize waste and maximize reuse whilst ensuring compliance to the required environmental regulations.
- Europe > United Kingdom (0.68)
- North America > United States > Texas (0.28)
- Water & Waste Management > Water Management > Lifecycle > Treatment (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (1.00)
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
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- Well Drilling > Drilling Fluids and Materials > Drilling fluid selection and formulation (chemistry, properties) (1.00)
- Well Drilling > Drilling Equipment (1.00)
- Health, Safety, Environment & Sustainability > Environment > Waste management (1.00)
- Facilities Design, Construction and Operation > Processing Systems and Design (1.00)
...19 21 6 13 13 3 1 5 3 3 3 8 4 2 3 RPM 31 15 18 5 11 10 3 1 4 2 2 3 6 3 1 Gel 0 28 18 21 6 11 10 4 1 4 3 3 3 6 5 2 Gel 10 40 31 40 10 17 15 6 3 9 3 4 3 10 8 5 PV 85 62 64 40 67 77 19 20 31 17 30 7 26 13 17 ...81 42 48 17 50 42 1 -1 13 1 8 25 19 4 2 Fluid Loss 6 10 10 8.6 6.8 6.4 NC NC 8.5 NC 8 NC 7.4 NC NC solids influences the brine lubricity and the presence of drilled / low gravity ...solids significantly reduces lubricity. Laboratory tests showed that the lubricity coefficient of the K-Fo...
...imitations. K-Formate brine was utilized up to maximum density of 12.5 ppg to reduce the impacts of solids in the mud. For the first time, maximum mud weight of 17.8 ppg was achieved operationally using mic...
...ty Stabilize polymers at higher temperatures Inhibit bacterial growth High tolerance to solids contamination Non-damaging to the reservoir Low corrosivity Good shale inhibition with ...
Abstract The Jurassic reservoirs of deep wells in Kuwait have traditionally been drilled with OBM. Barite is utilized as the weighting material in the OBM resulting damages to these reservoirs, thereby reducing the productivity to a significant extent. The higher oil to water ratio (95/5) of OBM limits the possibilities of identifying the micro fractures in reservoirs due to the limited conductive medium in OBM. Potassium formate WBM, with Manganese Tetraoxide as weighting material was successfully applied in HPHT wells overcoming these limitations. K-Formate brine was utilized up to maximum density of 12.5 ppg to reduce the impacts of solids in the mud. For the first time, maximum mud weight of 17.8 ppg was achieved operationally using micromax (Mn3O4) in this WBM. Also, for the first time in Kuwait, this kind of fluid was used to drill the section with the inclinations above 60° in deep wells. As a result of using K-Formate WBM in the reservoir sections, production increased significantly when compared to the wells drilled with OBM and barite. Wells were simulated easily without the presence of barite. Water based conductive medium gave better quality of image logs. Unlike other WBM's, K-formate WBM was stored for long periods, over a year in the mud plants without any damage to the mud properties. Recycling reduced the overall fluid costs in the subsequent wells drilled with K-formate WBM. Environmental damage due to the OBM spills and cuttings were completely avoided; K-formate WBM is highly bio-degradable under atmospheric conditions and is environmentally friendly. The experience and success gained with its use on the initial wells led to the planned usage of this WBM on all deep exploratory wells. This paper explains the experiences gained and the achievements made over the years with K-formate WBM used for drilling the deep HPHT wells.
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.98)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.98)
..., high anticipated CO 2, and high weight. A mechanical factor that affects hole enlargement is high solids loading required the water-based system to be evaluated rou-flow rates. High flow rates were used t...0 4.9 11.8 7.9 4.9 GFT Ligno·· 2.8 3.9 4.8 6.7 7.6 7.9 7.3 8.6 SA·· 2.3 10.4 12.1 Mod. Poly.·· 2.4 3.3 4.2 VaNS·· 0.3 0.7 1.3 ·The material balance Is a tool used to measure concentrations 01 products...
... seE 1953 J Summa..,. Lime-based drilling fluids are commonly used in applications that require solids tolerance, low and stable rheological properties, resistance to contaminants, and inhibition to sha...ive gelation of the mud at higher temperatures. Recent developments in drilling-fluid additives and solids-control equipment now permit the use of lime-based drilling fluids in high-temperature/high-pressur... an 18.5-HTHD lime-based fluid. Ibm/gal mud density. Success of the operation was the result of The solids-control system on the rig was also evaluated to improve careful well planning and prudent operation...
...inyl sulfonate l,3.7 and sulfonated maleic anhydride. 1.2.7 Most importantly, the low-gravity solids were maintained at low levels, and bentonite use was restricted. 11.750 sd at 11049 FEET...epth The two most troublesome contaminants considered on (It) Problems this well were low-gravity solids, including the addition of bentonite, and influxes of CO 2 5,000 to 6,350 Gumbo shale, bit balli...uck pipe, difficulties. In addition, special emphasis was placed on the efficiency CO 2 gas of solids-control equipment. The weekly mud samples were 12,600 to 14,600 CO 2, high pressure, lost circu...
Summary Lime-based drilling fluids are commonly used in applications that require solids tolerance, low and stable rheological properties, resistance to contaminants, and inhibition to shales. The use of lime-based systems previously was restricted to environments in which temperatures were lower than 300°F because of excessive gelation of the mud at higher temperatures. Recent developments in drilling-fluid additives and solids-control equipment now permit the use of lime-based drilling fluids in high-temperature/high-pressure (HTHP) environments. Amoco Production Co. recently used a lime-based mud to drill a well offshore Texas in an HTHP environment. Predetermination of the drilling-fluid objectives contributed to the success of the operation. First, the drilling fluid had to satisfy U.S. Environmental Protection Agency (EPA) environmental discharge requirements. Second, stuck pipe and lost circulation, prevalent problems in offset wells, had to be minimized. Third, the fluid had to be stable to temperatures of 350°F and densities to 18.5 lbm/gal and to be resistant to CO2 and to saltwater flows. A high-temperature, lime-based system was developed and maintained to meet these drilling-fluid objectives. This paper describes the planning used to select the mud system, development of the formulation in the laboratory, laboratory testing to determine treatments during the course of the well, and the performance of the drilling fluid. This experience provided a unique approach to both the formulation and maintenance of a lime-based fluid used in hostile environments. Introduction Amoco Production Co., New Orleans Region, successfully used a lime-based drilling fluid in an HTHP environment. Mustang Island Well A-110, offshore Texas, was drilled to a total depth (TD) of 17,352 ft. The well was logged with a bottomhole temperature (BHT) of 338°F >350°F, interpreted by Horner plot) with an 18.5-lbm/gal mud density. Success of the operation was the result of careful well planning and prudent operational practices. Improvements made to a rather conventional lime-based drilling fluid to obtain a high-temperature/high-density (HTHD) formulation contributed to the well's success. In hostile drilling environments, many wellbore problems must be overcome to operate at maximum efficiency. In wells of this type, invert oil muds normally are used because they resist contaminants, provide wellbore stability, and are stable at high temperatures; however, oil muds pose environmental problems, and cuttings transportation and disposal can be expensive, especially offshore. If lost circulation occurs while an oil-based fluid is used, circulation is difficult to regain. Therefore, special consideration was given to use of a water-based fluid on this well. During well planning, offset well information was gathered to define operational problems and to determine pore pressures. Data from Mustang Island Well A-111 No. 3, drilled in 1986, were used to determine the casing program and pore pressures (Figs. 1 and 2) for the new well. Each hole section was then analyzed for problems common to that section of hole and recorded (Table 1). From these problems, a mud system was selected on the basis of the success of offset mud programs and overall economics. Four drilling-fluid objectives were then established for the well. The drilling fluid must (1) satisfy EPA environmental discharge requirements; (2) eliminate or minimize offset well problems; (3)remain stable at a temperature of 350°F with a density of 18.5 lbm/gal;and (4) be resistant to such contaminants as CO2and salt. Existing literature was researched to focus on the HTHP portion of the well. Research revealed that many of the typical dispersed fluids used in high-temperature environments contained a surfactant or a chromium compound to promote rheological stability. Such additives could prevent discharge of cuttings or mud into the Gulf of Mexico. The literature also showed that lime-based fluids could solidify as temperatures approached 300°F. This type of system was the most desirable because it directly addressed the problems listed in Table 1. The literature indicated that a high-temperature lime mud could be formulated with some new additives.Laboratory testing was begun to formulate an HTHD lime-based fluid. The solids-control system on the rig was also evaluated to improve control of low-gravity solids. Such control was considered essential for any potential water-based drilling fluid to control rheological instability. Low-gravity solids or excessive additions of bentonite can lead to rheological instability, which, in turn, can cause lost circulation. The addition of two centrifuges was found to be cost-effective in controlling solids and was used during the drilling of the well (Table 2). From the literature and laboratory work, a lime-based fluid was developed that showed promise in addressing the drilling objectives while remaining stable under hostile environments (Tables 3 and 4). A plan was developed that required laboratory testing during the course of the well and direct communication between the Baroid Drilling Fluids and Amoco personnel to discuss real or potential problems. This paper discusses the reasons for the use of the lime-based flulid, the formulation of the drilling fluid, the testing to determine the proper product mix, and the results of these efforts. History of Lime-Based Muds Lime-based muds were used widely throughout the 1940's and 1950's. They were considered to be an inhibitive fluid with a tolerance to such common contaminants as salt, cement, and anhydrite. The rheologic properties of lime-based muds remain stable and low, even in a high-solids environment. They can be made with nearly any type of makeup water and easily maintained. As wells were drilled into deeper and hotter environments, however, severe gelation occurred; in the most severe cases, cementation of the mud occurred in the hole. Therefore, use of lime-based muds was restricted to environments with temperatures lower than 300°F and were discarded when a burned odor or severe gelation was observed during circulation after the mud was allowed to remain static in the hole. With more experience with lime-based muds, it was generally thought that a lower lime content could be used to increase the thermal stability of the mud at some expense toward inhibition. Thereafter, lime-based muds were classified as low-, medium-, or high-lime mud systems.
- North America > United States > Texas (0.44)
- North America > United States > Louisiana > Orleans Parish > New Orleans (0.24)
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