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Fracturing materials (fluids, proppant)
Effective Fracturing Stimulation in the BRN Field in Algeria Using a Residue Free Gelled Fluid System
Forno, Luca Dal (eni Algeria) | Latronico, Roberto (eni Algeria) | Mohammed, Omar (Halliburton) | Kateb, Mahmoud (Halliburton) | Rispler, Keith (Halliburton) | Ainouche, Dalil (Halliburton) | Squires, Scott (Halliburton) | Petteruti, Ernesto (eni Algeria) | Fragola, Daniele (eni Algeria) | Allal, Mohammed A. (Sonatrach) | Hachelaf, Houari (Sonatrach) | Albani, Danilo (eni Algeria) | Hamdane, Toufik (Sonatrach) | Carpineta, Gabriele (eni S.p.A)
Abstract Hydraulic fracturing for well performance optimization has been implemented for many years in BRN field in north-eastern part of Algeria, operated by Groupement Sonatrach-Agip (a JV between ENI and Sonatrach). Because of unfavorable petro-physical properties of the reservoir, some challenges have been encountered in avoiding any additional damage to the fracture faces and to facilitate the post-job treating fluids flowback. Effective fracturing treatment designs should consider preventive actions for possible fracture conductivity impairment, such as damage attributed to stress, proppant embedment, and damage caused by fracturing fluid residues. Correct proppant selection can minimize effects from stress and embedment, while a suitable fluid system can minimize conductivity impairment from gelling agent solid residue. Traditional guar-based fluid systems, which are often a preferred choice in the industry for fracturing operations, can have damaging effects on fracture conductivity attributed to inherent insoluble residue that can plug proppant pack pore spaces. Implementing a less damaging fluid system can not only maximize retained conductivity, but furthermore provide longer effective fracture half-lengths which may result in more efficient treatment fluid recovery. Therefore, to overcome such issues, a new fracturing fluid has been developed, leaving little or no residue after breaking. Moreover, this fluid system can be tailored to a wide variety of bottom-hole conditions and has comparable properties to guar-borate fluids with respect to proppant transport capacity and rheological characteristics (e.g. viscosity building and breaking behaviors). This paper presents the first successful implementation of this novel fluid system in the BRN field in Algeria for improving the water injection performance of a well characterized by a tight sandstone reservoir. Field data collected after performing the propped fracturing treatment confirm the effectiveness of the fracturing fluid design. Specifically, the following topics will be extensively described within this paper: Characteristics of the BRN field and history of conventional guar-base fluid systems used previously within this field; Specifics of the near residue free fluid system (cross-linker types, pH requirements, etc.); Design considerations for the implementation in the BRN field of this novel fracturing fluid; Results of post fracturing water injection performances.
- Geology > Geological Subdiscipline > Geomechanics (0.66)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (0.54)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.46)
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (1.00)
- Reservoir Description and Dynamics > Fluid Characterization > Fluid modeling, equations of state (1.00)
Abstract For a successful hydraulic fracturing operation, two of the most important properties required from fracturing fluids are transport proppant into the fractured zone and minimum damage to formation and proppant pack conductivity. As the fluid is pumped downhole, it experiences thermal and shear thinning. Shear recovery and thermal stability are critical in terms of successful fracture creation and proppant placement. These fluid properties can be controlled by proper selection of crosslinker and linkable groups. Thermal stability of fluid at high temperatures can be increased by proper selection of gel stabilizers and it also reduces the amount of gelling agent to be used. Conventional gel stabilizer contains sulfur which could contribute to H2S gas when consumed by sulfate reducing bacteria. H2S gas is not only corrosive in nature but also harmful to health and thus, although it performs well, several operators seek sulfur-free stabilizers that can perform equivalent to sulfur-based compounds. This paper describes a sulfur-free gel stabilizer developed for enhancing the stability of fracturing fluid, allowing a lower concentration of gelling agent. This gel stabilizer is sulfur-free, nonhazardous, and biodegradable. It also provides better stability for fluids compared to conventional sulfur containing gel stabilizers. Further showcased is the improvement in stability of crosslinked fracturing fluid using the sulfur-free stabilizer under high temperature (HT) conditions of 280 to 320°F. Rheological tests performed using a Chandler high-pressure/high-temperature (HP/HT) viscometer with and without stabilizer are discussed. Results shows a significant change in terms of fluid stability in the presence of this new stabilizer as it provides better stability compared to conventional sulfur containing stabilizer. Also, shear sensitivity tests performed under multiple high shear rate cycles between 100-935-1700 s showed excellent shear recovery after every high shear cycle by completely rehealing in less than 30 seconds.
- Research Report > New Finding (0.48)
- Research Report > Experimental Study (0.48)
Fracturing Fluid Rationalization: First Dual-Viscosity Fracturing Fluid Application in the Middle East
Mira, Ali (Sahara Oil and Gas) | Samir, Mohamed (Sahara Oil and Gas) | Naby, Mohamed Abdel (Sahara Oil and Gas) | Mohamed, Nelly (Schlumberger) | Rojas, Jose (Schlumberger) | Kamar, Ahmed (Schlumberger) | El Sebaee, Mohamed (Schlumberger)
Abstract Dual-viscosity fluid is a fracturing fluid that has been recently introduced to cover a wide range of fracturing applications varying, from a non-delayed to delayed fluid system for treatments in low to moderate to high temperatures, respectively. Reducing the impact of the pressure effect of traditional borate cross-linked systems, the system crosslinker is compact and delivers a relatively high concentration of crosslinker per unit volume; it is also compatible with current metering pumps, covering a range of treatment rates compared to the current fluid system, and this can simplify logistics on location. The North Bahariya oil fields are onshore fields located in the Western Desert of Egypt and operated by Sahara Oil and Gas Company (SOG). The fields contain proven oil reserves in two sandstone packages at relatively shallow drilling depths (6,500 ft. subsea) in the Abu Roash "G" member (A/R G) of Cenomanian (Cretaceous) age. These sandstones comprise the main reservoirs in the field. During the last 4 years, the introduction of various techniques has led to a fourfold increase in the production from these fields. This success story is mainly the result of using the new hydraulic fracturing methods such as channel fracturing technique and continuous improvement of the fracturing treatments. SOG has been at the forefront in applying novel technologies to optimize the fracturing fluid treatment by using the dual-viscosity fracturing fluid to improve the wells potential. This technology has been implemented in Abrar field. As seen in case studies, very positive results have been seen in both zones of the A/R G formation in terms of improvement in the well performance. Experiences in Abrar field illustrate how to optimize the production rate in a marginal field by optimizing the hydraulic fracturing treatment fluid and how to build on this success for subsequent fields while pushing the innovation envelope further.
- Africa > Middle East > Egypt > Western Desert > Greater Western Dester Basin > Abu Gharadig Basin > North Bahariya Concession > Abrar Field > Abu Roash Formation (0.99)
- Africa > Middle East > Egypt > Western Desert > Greater Western Dester Basin > Abu Gharadig Basin > Abu Roash Formation (0.99)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.94)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.94)
Supramolecular Viscoelastic Surfactant Fluid for Hydraulic Fracturing
Yang, Jiang (RIPED-Langfang, PetroChina) | Lu, Yongjun (RIPED-Langfang, PetroChina) | Zhou, Caineng (RIPED-Langfang, PetroChina) | Cui, Weixiang (RIPED-Langfang, PetroChina) | Guan, Baoshan (RIPED-Langfang, PetroChina) | Qiu, Xiaohui (RIPED-Langfang, PetroChina) | Liu, Ping (RIPED-Langfang, PetroChina) | Ming, Hua (RIPED-Langfang, PetroChina) | Qin, Wenlong (Xi'an Petroleum University) | Ji, Sixue (Xi'an Petroleum University)
Abstract This paper studied a new fracturing fluid based on a supramolecular complex of associative polymer and vsicoelastic surfactant. The crosslink complex gel was based on weak physical attractive forces such as van der waals, hydrogen bonding and electrostatic interaction between associative polymer and wormlike micelle of viscoelastic surfactant. The fluid contained surfactant ten times less than that of conventional viscoelastic surfactant fracturing fluid. The combination of viscoelastic surfactant and associative polymer synergistically enhances the viscosity ten times more than that of the individually components alone. The fluid system was optimized by experimental design. The microstructure of wormlike micelle was verified by cryo-transmission electron microscopy. The fluid is shearing-stable at high temperature for 1 hour. The dynamic rheological properties of the new VES fluid showed high viscoelasticity, in which elastic moduli is higher than loss moduli at angular frequency 0.1 rad/s. The proppant transport test in a large-scale fracture simulator showed good proppant suspension ability. The fluid has 50% lower formation damage than that of conventional guar. The fluid was prepared with less additives and formed gel instantly which can be mixed on the fly in the field. The gel can be completely broken with almost no residue. Field application of the new fracturing fluid in a gas field showed the enhancement of gas production over 100%. The fluid has 20% lower friction pressure than that of guar fluid. Hence, the new supramolecular viscoelastic surfactant gel is an effective fracturing fluid with less formation damage.
- Africa (0.47)
- North America > United States (0.29)
- Asia > China (0.29)
- Asia > China > Inner Mongolia > Ordos Basin > Sulige Field > Ordos Formation (0.98)
- Asia > China > Inner Mongolia > Ordos Basin > Sulige Field > 8th section of Shihezi Formation (0.98)
- Asia > China > Inner Mongolia > Ordos Basin > Sulige Field > 1st section of Shanxi Formation (0.98)
- North America > United States > Louisiana > China Field (0.91)
Abstract Proppants are required in hydraulic fracturing operations in the oil and gas industry. They consist of solid particles with specific strengths and are used to keep the rock fractures open in order to increase well production. They can be naturally occurring sand grains or artificial ceramic materials. Studying the acid resistance of proppants is important. Acids are needed to remove the scale and clays that affect the fracture conductivity. This study investigated the different factors affecting the interactions between mud acid and sand proppants. Several experiments were conducted using the aging cell with mud acid (3 wt% HF, 12 wt% HCl) up to 300°F. The effects of temperature, soaking time, and static and dynamic conditions were examined. The supernatant of solubility tests was analyzed to measure total silicon concentrations using ICP-ES. The proppant was sieved before and after the experiments. Following that, the residual solids were dried and analyzed using a scanning electron microscope (SEM). The results showed that sand proppant is soluble in regular mud acid, nearly 10 wt% dissolved in some cases. The amount of proppant dissolved increased with temperature, soaking time, concentration, and dynamic conditions. The fines generated and the changes in grain size distribution are detrimental to the proppant conductivity. This work will help to achieve a better acid treatment design when sand proppant is used.
Non-Radioactive Detectable Proppant First Applications in Algeria for Hydraulic Fracturing Treatments Optimization
Forno, Luca Dal (eni Algeria) | Latronico, Roberto (eni Algeria) | Saldungaray, Pedro (CARBO Ceramics) | Petteruti, Ernesto (eni Algeria) | Fragola, Daniele (eni Algeria) | Allal, Mohammed A. (Sonatrach) | Hachelaf, Houari (Sonatrach) | Albani, Danilo (eni Algeria) | Hamdane, Toufik (Sonatrach) | Carpineta, Gabriele (eni S.p.A)
Abstract Bir Rebaa Nord (BRN) and Bir Sif Fatima (BSF) fields, operated by Groupement Sonatrach-Agip (GSA, a JV between ENI and Sonatrach), are located in the Berkine basin in north-eastern Algeria. These fields are characterized by oil-bearing sandstone reservoirs with low to medium petro-physical properties. During the development phase, to counteract the effect of pressure depletion, water and gas injection was implemented for reservoir pressure maintenance. In addition, due to the increasing water cut, artificial lift systems were employed to effectively produce these fields. Hydraulic fracturing has been implemented in GSA since year 2000 to improve well performance, both in terms of productivity and injectivity for oil producers and water injectors respectively. The fracturing process has been improved over the years regarding operational procedures, enhanced reservoir knowledge and implementation of new technologies towards resolving the many uncovered challenges. Changes to the perforation strategy, fracturing fluids formulation, rock mechanics studies and design of proppant schedules are examples of enhancement to the fracturing practice that have been implemented in the recent years. One of the uncharted matters in GSA, coming out from the post-job data re-processing, was the necessity of a precise characterization of the hydraulic fractures vertical coverage. The presence of several sandstone layers with different properties brought questions if the fracture had grown into an unwanted zone or may had not properly covered the entire target formation. Moreover, fracture height is an essential parameter for frac models calibration. Its accurate determination drastically reduces the margin of error in treatment net pressure matching, helping to more precisely established fracture half-length and width, stress profile and, last but not least, achieving a calibrated model for future operations in the same area. This paper describes the successful implementation on two water injector wells of a novel non-radioactive detectable proppant for the first time in Algeria. The taggant material within the proppant has been located by comparing the pulsed neutron capture cased-hole logging passes registered before and after the hydraulic fracturing treatments. The detectable compound does not affect proppant properties and, in addition, its non-radioactive nature reduces the timing for materials delivery and eliminates the HSE risks linked to other tracing methods. The pulsed neutron measurements evaluation provided valuable information regarding fractures confinement, avoidance of contact with undesired layers and possible presence of cement channeling. Furthermore, combined with sonic logs and cores data, it helped refining the geo-mechanical model for future interventions design in the same reservoirs.
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Sandstone (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Passive Seismic Surveying > Microseismic Surveying (0.46)
- Africa > Middle East > Algeria > Eastern Algeria > Berkine Basin (Trias/Ghadames Basin) (0.99)
- Africa > Middle East > Algeria > Ouargla Province > Berkine Basin (Trias/Ghadames Basin) > Block 402a > Bir Sif Fatima Field > BSF-1 Well (0.94)
- Africa > Middle East > Algeria > Ouargla Province > Berkine Basin (Trias/Ghadames Basin) > Block 401a > Bir Sif Fatima Field > BSF-1 Well (0.94)
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (1.00)
- Reservoir Description and Dynamics (1.00)