Not enough data to create a plot.
Try a different view from the menu above.
slurry
Clinker Slurry for Cementing Across Salt Formations
Huang, Hongfei (College of Materials Science & Engineering, Nanjing Tech University) | Wang, Chunyu (College of Materials Science & Engineering, Nanjing Tech University (Corresponding author)) | Yao, Xiao (College of Materials Science & Engineering, Nanjing Tech University (Corresponding author)) | Geng, Chenzi (College of Materials Science & Engineering, Nanjing Tech University)
Summary Potassium chloride (KCl) is more effective in preventing salt layer dissolution than sodium chloride (NaCl) while cementing across salt formations. This paper studied the effect of KCl on the properties of cement slurry and found that KCl worsened the flowability of cement slurry. Experimental evidence confirmed that an alkaline environment promoted the dissolution of gypsum, leading to its reaction with KCl to produce syngenite. A large amount of needle-shaped syngenite caused the cement slurry to lose flowability. In addition, silica flour slurry was designed to prove the formation of syngenite and the effect of syngenite on the rheological property of the slurry. In a new way, clinker was used to prepare slurry containing KCl to prevent the generation of syngenite. The effect of KCl on the properties of clinker slurry was evaluated. The dissolution experiment of halite in clinker slurry filtrate proved that KCl had a strong ability to inhibit the dissolution of halite.
- Asia (0.93)
- North America > United States > Texas (0.28)
Drilling and Well Construction in Lean Clearances in Northern Region of Pakistan
Iftikhar, Ali (Mari Petroleum Company Limited, Islamabad, Pakistan) | Nasrumminallah, Muhammad (Mari Petroleum Company Limited, Islamabad, Pakistan) | Rasheed, Hassaan (Dowell Schlumberger, Islamabad, Pakistan) | Sabir, Shahid Majeed (Weatherford Oil Tools ME, Islamabad, Pakistan) | Sharif, Yasir (Weatherford Oil Tools ME, Islamabad, Pakistan)
Abstract Subject well is an exploratory well with a target depth of +/- 6000M, in one of the most challenging northern region of Pakistan. Well has multiple challenges with regards to drilling and well construction the least to mention are losses, borehole instability, intercalated formations, with steep dips along with a fault. Lean clearances in a five Casing Strings well construction were a requirement to isolate the problematic zones for safe drilling, this included running of longest 16" Liner for the first time in Pakistan, borehole enlargement of 14 3/4" to 16", later on running of 13 5/8" Flush x 13 3/8" coupled connection casing with narrow annular clearance, with customized Cementing Job to avoid surging. Running of 16" liner, drilling and construction of next section called for robust technical applications that includes drilling with aerated mud, running of 16" Liner with liner hanger for the first time in Pakistan, borehole enlargement while overcoming the various challenges as various formations (limestone, Sandstones, Clays) were drilled and later enlarged using hydraulic Under Reamer. Fit for purpose mud was used while drilling and further optimized to solid free for the smooth running of 13 5/8" × 13 3/8" Casing through lean clearance of 16" Liner. Casing running strategy has been devised to avoid Surge to formation at the same time ensuring it gets to bottom without any held up. The objectives of the section were met successfully. The paper will serve as a platform for other Operating companies in Pakistan to benefit from the lessons learnt and best drilling practices
- Well Drilling > Drilling Fluids and Materials > Drilling fluid selection and formulation (chemistry, properties) (0.90)
- Well Drilling > Drilling Operations > Running and setting casing (0.71)
- Well Drilling > Casing and Cementing > Casing design (0.70)
- Well Drilling > Drillstring Design > Torque and drag analysis (0.69)
Step-Change in Cement Design Assures Well Integrity Under Dynamic Stress
Mahmood, Ahmad A. (Schlumberger, Islamabad, Pakistan) | Jan, Usman A. (Schlumberger, Islamabad, Pakistan) | Khan, Anum Y. (Schlumberger, Islamabad, Pakistan) | Rasheed, Hassaan (Schlumberger, Islamabad, Pakistan) | Salazar, Jose (Schlumberger, Islamabad, Pakistan) | Shah, Khurram A. (MOL, Islamabad, Pakistan) | Khan, Shahjahan (MOL, Islamabad, Pakistan)
Abstract The Kohat Plateau in Pakistan features major Gas and Condensate producing fields with majority of the blocks owned and operated by two of the country's biggest E&P Operators. Operators are known to frequently encounter severe drilling challenges, and over time, have devised certain technology solutions that have helped curtail the major drilling challenges to a good extent, helping improve the time and cost expended in reaching the target depths. However, the problems arising after the Drilling cycle – foremost being Sustained Casing Pressure (SCP) – require expensive remedial treatments and loss of production; this paper presents a solution to this particular challenge of SCP including in-depth cause analysis, treatment design and implementation. In the analysis stage, the drilling data of wells experiencing SCP in one of the Casing annuli was reviewed to pinpoint possible areas of compromised well integrity. It was observed that sections having good Cement bonds and sufficient Top of Cement in the annulus also became compromised over time, indicating operations conducted after the drilling phase could be responsible for the annular fluid migration, and hence SCP. It must be noted that extensive drill-stem tests to assess the reservoir economics as well as production pressures generate significant dynamic stress on the well structure. Through the use of custom stress-analysis software for annular Cement, it was concluded that it is this stress that causes the primary isolation of the constructed well, the annular Cement, to fail allowing annular migration of formation fluids. A new class of stress-resistant, auto-repair Cements was seen to resist any mechanical failure under stress enabling Operators to drill wells with lasting structural integrity. Mechanical properties including Young's Modulus, Poisson Ratio and Annular Expansion co-efficient were analyzed to design a Cement system capable of withstanding the applied stress. The first in-country application was conducted as the Intermediate-section Cementing in a new well. The system exhibited good isolation with average 10mV amplitude (free pipe amplitude 51 mV) in Cased Hole bond logs and no annular pressure is observed till date in the section more than 02 years after the primary cementing operation. This design approach was subsequently extended to other fields, with successful applications that reduced, and in certain cases, eliminated the need for remedial work. By presenting a detailed field application of flexible and self-healing Cement, the paper puts forth a general, stepwise approach for the selection of a Cement design that promises lasting annular isolation and minimizes the risk of communication behind the casing.
- Asia > Pakistan (0.51)
- North America > United States > Texas (0.28)
Evaluating the Sealing Performance of Plug and Abandonment Cement Systems Under Downhole Conditions
Roijmans, Roel F. H. (Shell Global Solutions International B.V. (Corresponding author)) | Wolterbeek, Timotheus K. T. (Shell Global Solutions International B.V.) | Cornelissen, Erik K. (Shell Global Solutions International B.V.) | Keultjes, Wout J. G. (Shell Global Solutions International B.V.)
Shell Global Solutions International B.V. Summary Microannuli are an important cause of post-abandonment seepage along abandonment plugs set in wells. Autogenous cement shrinkage, occurring when the cement sets, is a contributing factor to the formation of such flaws. Cement shrinkage and its potentially deleterious effects can be mitigated by using a properly designed and placed expanding cement system. Reliable evaluation of cement plugs' sealing performance requires testing under elevated temperature and pressure conditions representative for downhole conditions. In this contribution, two laboratory setups designed for this purpose are described, namely (i) smallscale tests on 2-in. In both setups, plugs are cured and tested under downhole conditions inside sections of steel pipes. These pipes are equipped with lateral pressure-temperature sensors, which allow the recording of stresses that develop on the cement-steel interface when the hydrating cement plug expands. Using this bespoke cement testing equipment, a strong positive correlation was found between the amount of interface stress buildup and the sealing performance of the set cement plug against gas flow. This demonstrates that cement systems that expand effectively under downhole conditions can reduce post-plug and abandonmen (P&A) seepage risks. Unfortunately, standard industry methodologies to verify the effectiveness of the cement expansion additives (CEAs) do not take into account in-situ well conditions. To allow the industry to still evaluate cement plug sealing performance with low complexity while maintaining reliability, a conventional ultrasonic cement analyzer (UCA) was modified to enable simultaneous measurement of interface stress development. For this contribution, multiple cement slurries were cured and evaluated in the 2-in. Strong correlations were found among the stress buildups in all three setups. This enables the modified UCA test results to be used as a proxy for sealing performance of P&A cement plugs under downhole conditions. Introduction The objective of a well P&A operation is to achieve permanent zonal isolation among subsurface formations and the environment (Vrålstad et al. 2019). Failing to meet this key objective can result in liquid or gas seepage across different formations exposed to a wellbore, into potable groundwater resources, or potentially even back to surface, leading to unwarranted formation charging, sustained casing pressure (i.e., any measurable casing pressure that rebuilds after being bled down), surface casing vent flow (i.e., a condition where fluid or gas is flowing from the surface casing vent assembly), and loss of societal reputation.
Summary In the placement process of the cement slurry, treatment fluids such as the spacer are pumped ahead of the cementitious slurry to minimize the contamination of the slurry by drilling fluid and ensure superior bonding to the casing and formation. The spacer discussed in this work can harden with time and act as a settable spacer. This characteristic can be an advantage for well integrity if some spacer pockets are left in the annulus. Rheological compatibility of different mixtures of the spacer with oil-based drilling fluid (OBDF) has been studied using a rheometer, and the resulting R-factor, which indicates the degree of compatibility between fluids, has been calculated. An increase in the flow curve was observed for the mixture of the fluids. However, based on the R-index, these fluids are compatible with displacement in the wellbore. A nonionic surfactant, typically used in conventional spacers acting as an emulsifier and a water-wetting agent, was used in the hardening spacer design. The results show that the addition of OBDF to hardening spacer containing surfactant can increase viscoelasticity. Hardening spacer containing surfactant can successfully reverse the OBDF emulsion. By performing a small-scale mud displacement experiment, we observed that surfactant can improve the wall cleaning efficiency of the spacer while having minimal impact on the bulk displacement.
- Europe (1.00)
- North America > United States > California (0.28)
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.48)
Zonal Isolation Material for Low-Temperature Shallow-Depth Application: Evaluation of Early Properties Development
Agista, Madhan Nur (University of Stavanger (Corresponding author)) | Khalifeh, Mahmoud (University of Stavanger) | Saasen, Arild (University of Stavanger) | Yogarajah, Elakneswaran (Hokkaido University)
Summary Shallow-depth cementing presents unique challenges due to its low temperature and low pore pressure characteristic. The curing process of the cementitious material is typically prolonged at low temperatures resulting in a delayed curing process. The use of a low-density slurry to mitigate low pore pressure introduces another challenge, as it leads to a reduction in the final compressive strength. On the other hand, the operation requires the material to develop enough strength swiftly to be able to efficiently continue the next drilling operation. In addition, the presence of flow zones such as shallow gas and shallow water flow increases the complexity of the cementing process. There have been many developments in cementitious materials for shallow-depth cementing such as rapid-hardening cement and gas tight cement. However, there is little research focusing on the performance evaluation of each material at low-temperature conditions. This paper aims to present a thorough material evaluation for low-temperature shallow-depth cementing. The incorporated materials are American Petroleum Institute (API) Class G cement, rapid-hardening cement, gas tight cement, and geopolymer. Geopolymer is included to evaluate its potential as the green alternative to Portland-based cement. The sets of characterization were conducted during the liquid, gel, and solid phases. The samples were prepared under wide-ranging low temperatures and typical bottomhole pressures for shallow sections. The result shows different performances of each material and its behavior under low temperatures such as prolonged strength development and low reactivity, which necessitates further development of these materials.
- Asia (0.93)
- Europe > United Kingdom (0.46)
- North America > United States > Texas (0.28)
- Geology > Geological Subdiscipline > Geomechanics (0.69)
- Geology > Mineral > Silicate (0.69)
_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 210003, “What To Do With Produced Solids After Separation: Dewatering, Transport, and Disposal,” by Charles H. Rawlins, SPE, eProcess Technologies. The paper has not been peer reviewed. _ The primary role of offshore solids handling is to remove and dispose of produced solids properly, without interruption or shutdown. Most sand-management studies focus on the separation component only. However, 80% of the capital expenditure (CAPEX) of the process is attributed to separating devices, and 80% of the operating expenditure (OPEX) involves dewatering, transport, and disposal (DTD). The complete paper outlines questions that must be asked during facility design and provides guidelines, calculations, and examples on each of the steps of the sand-handling process to be implemented after separation. Facilities Sand Management (FSM) FSM refers to the solids-handling processes in the hydrocarbon production and processing system from the wellhead to custody transfer, based on engineering knowledge and a certain degree of skill. FSM is not a waste-stream-treatment exercise but a critical flow-assurance issue. Production and uptime are maintained (or increased) even when solids are present, while the operating costs are minimized or reduced. This is accomplished through the use of a proper facility design incorporating the five steps of sand management to fully manage and handle the sand produced. Each step must be integrated into the facility design. The authors identify these steps as follows: 1. Separate—Partition solid particles from liquid, gas, or multiphase flow into a separate stream. 2. Collect—Gather the partitioned solids into a single central location and remove them from the process pressure and flow. 3. Clean—Remove adsorbed hydrocarbon contaminants from the gathered sand particles with an attrition scrubbing system. 4. Dewater—Remove free water from the sand slurry to minimize the disposal volume dramatically. 5. Transport—Transport the solids to a final disposal location. Role of DTD An improperly designed DTD system likely will cause a congestion of the entire solids-management system. The starting point for discussion, when considering the FSM approach, is to identify the proper (final) disposal route of the solids and then work backward to meet that requirement. The Pareto principle (or the 80/20 rule) applies as equally to sand management as it does to macroeconomics. The 80/20 rule applied to FSM entails that 80% of the CAPEX of an FSM system can be attributed to the separating device (Step 1), while the work accounting for 80% of the OPEX of the FSM system is associated with the DTD method. The clear CAPEX ramification is probably why so much focus has been placed on separating devices. In the long term, however, the OPEX of sand management should be considered.
Summary A new approach for the synthesis of bio-inspired polymer microcapsules used to encapsulate chemical additives and designed for small molecule release and delivery is shown here. The flexibility to design different microcapsules using an emulsion template results in various encapsulated additives for a new polymer technology platform. The base materials for encapsulation are polyaramids that are highly crosslinked membrane shells around an empty core. These empty capsules provide a carefully designed space to site-isolate chemical additives, various encapsulants for encapsulation, and delivery where needed. These microcapsules have demonstrated that after being formed from a simple one-pot synthesis between two immiscible solutions, a new method for encapsulation for applications in ordinary Portland cement is possible. The final product is a free-flowing solid that can be easily added to any fluid application. Experimental results show that when added to a basic cement slurry design, cement responds to the release of a salt accelerant as measured using standard oilfield equipment, like the pressurized consistometer, which measures changes in viscosity and thickening times. In one of many applications, the consistency of cement remains favorable at 20 Bc after adding encapsulated calcium chloride for up to 5 hours, for example. Over time, various capsules caused cement slurries to set at right angles at various thickening times with the controlled release of encapsulated calcium chloride. This new approach for encapsulation is promising for the chemical and energy field.
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (21 more...)
Novel Cement Design for Water Shutoff Application in North Kuwait Heavy Oil Field
Pullanikkottil, S. (Superior Energy Services) | Ibrahim, M. (Superior Energy Services) | Elghoul, S. (Superior Energy Services) | Bosilca, D. (Shell Kuwait Heavy Oil ETSA) | Gupta, P. (Kuwait Oil Company) | Al-Hammadi, E. K. (Kuwait Oil Company) | Al-Sairafi, F. A. (Kuwait Oil Company) | Abdullah, A. S. (Kuwait Oil Company) | Al-Ajmi, A. M. (Kuwait Oil Company) | Monteiro, K. (Kuwait Oil Company)
Abstract Kuwait Oil Company (KOC) have been actively recovering hydrocarbons from Heavy-oil reservoirs located in the Northern Kuwait (NK) Fields. Northern Kuwait Heavy Oil (NKHO) reserves are mainly located in two major fields: Field-1 (cold well) and Field-2 (thermal well). Currently, this heavy oil field is in the developmental phase, and KOC plans to add additional wells yearly. Field-2 is a thermal field, currently producing with a water cut of approximately 45%. Typically, water coning is a major challenge that hinders thermal recovery in a heavy oil reservoir with a bottom or boundary aquifer. This situation typically occurs when the production zone is near an aquifer or a water-bearing formation with a permeable connection, based on the ratio of horizontal to vertical permeability between the oil production zone and water formation. Coning occurs with pressure drawdown, causing water to migrate from the bottom to the wellbore. This is strictly a near-wellbore phenomenon that occurs only once the pressure forces drawing fluids toward the wellbore exceed the natural buoyancy forces that segregate gas and water from oil. Coning is a rate-sensitive phenomenon generally associated with high production rates. Although it can be controlled by decreasing the production rates, this approach is unfavorable because oil production is reduced and water production impacts the economic life of reservoirs and ultimate recovery. Moreover, it increases the operating expenses such as pumping, water/oil separation, and equipment costs. Additionally, excess water production causes wellbore corrosion, scaling, and sand production problems. Because of the chemical complexity of the produced water, its disposal is a major environmental concern. This also increases the disposal costs. Therefore, developing a proper and economical method to shut off or lower excess water has become one of the most significant concerns of the KOC in the NKHO field. Field-2 is a relatively new emerging field with increased intervention complexity due to an increase in water cuts. Early remedial job trials using conventional thermal slurries were unsuccessful in Field-2. This study illustrates the deployment of a novel cementing solution to address the challenges associated with conventional thermal cement for low-pressure, low-temperature, water-shut-off cement squeeze jobs. The slurry design and approach have good potential for vast applications in Kuwait and heavy oil fields worldwide.
- North America (1.00)
- Asia > Middle East > Kuwait (1.00)
Systematically Study and Practice for Thermal Well Integrity in Liaohe Oilfield
Tong, Deshui (Liaohe Oilfield of PetroChina, Panjin, Liaoning province, China) | Liu, Mingtao (Liaohe Oilfield of PetroChina, Panjin, Liaoning province, China) | Xiong, Jimin (Liaohe Oilfield of PetroChina, Panjin, Liaoning province, China) | Chen, Ping (Liaohe Oilfield of PetroChina, Panjin, Liaoning province, China)
Abstract Liaohe Oilfield has developed heavy oil for more than 40 years, and accumulated a lot of experience in research and practice for well integrity under Cyclic Steam Stimulation, Steam Flooding, SAGD, In-situ Combustion. This paper will introduce the systematical achievements, including well completion design, casing selection, cementing slurry, string attachment, etc. Based on the continuous study of fundamental principles, thermal casing, details of pre-stress method and industrial evaluation, the well completion design method has been optimized and the practicality has been checked ultimately. In particularly, the pre-stress method has been deeply studied through experiments and calculations. We have made a further improvement on string attachments. According to thermal recovery environment and low-cost requirement, a Portland cementing slurry characterized with low Young’s modulus, high compressive strength, and good temperature resistance, has been researched and used in field. The pre-stress method for the completion string design is testified to be effective in some extent, because the stress pre-imposed can reduce the string stress and minimize the wellhead growth in thermal recovery. The newly researched cementing slurry has been systematically tested in laboratory, the results are excellent: Young’s modulus ≤6, compressive strength ≥21MPa, temperature resistance 350°C, cost lower than 1000$/t. Casing used in thermal well should have a good performance of collapse strength, and the thickness to diameter ratio is important as well as the premium connection. The newly designed anchor with 6-cylinder anchor claws attached the completion string can adapt with softy and hard stratum. With the standardization of all the measures used in Liaohe oilfield, the thermal well integrity becomes better and better. The statistical data shows that the casing damage rate lowered 34%, and the life of the thermal well prolonged at least 2 years on average. Some contents in this paper are novel, such as the result of the pre-stress experiment, Portland cementing slurry with low-cost and good performance, newly designed anchor, etc. We believe all the experience accumulated and introduced in this paper could give some useful directives for thermal well integrity all over the world.
- Geology > Geological Subdiscipline > Geomechanics (0.88)
- Geology > Petroleum Play Type > Unconventional Play > Heavy Oil Play (0.54)