Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Results
Investigating Optimized Well Placement in San Andres Tight Oil Dolomite Reservoir by Integrated Reservoir Modeling Approach
Yang, Junjie (Baker Hughes, a GE Company) | Karam, Pierre (Baker Hughes, a GE Company) | Cozyris, Kristian (Baker Hughes, a GE Company) | Hustak, Crystal (Baker Hughes, a GE Company) | Doherty, James (Riley Exploration โ Permian, LLC) | Allen, Carmen (Riley Exploration โ Permian, LLC)
Abstract As a well-known tight oil dolomite reservoir in Texas, San Andres formation has attracted broad attention about horizontal drilling and development strategy. To optimize the oil recovery and assetโs economics, the aim of the study was to use an integrated approach to understand reservoir heterogeneity and performance, determine optimal landing zone and its impact on production, understand fracture geometry using different pumping schedules, and the optimal cluster spacing. In addition, the potential benefit of a refrac and infill drilling program was also investigated. To tackle the optimization problem, an integrated reservoir modeling workflow was developed. Starting with a 1-D geomechanical model which captures the in situ stress profile and rock mechanics, hydraulic fracture modeling was developed to history match the treatment process, and therefore a comprehensive fracture geometry can be estimated. In the interim, a geological model with populated reservoir properties was established based on the offset data including petrophysical logs, imaging logs and cores. After calibration, the dynamic reservoir model was built to test multiple sensitivity runs for an optimized field development strategy. Geological modeling separated the field into two models to study the variation of properties on the east and west side. The east section shows a higher porosity and lower saturations. Those water saturations increase below the main pay zone indicating a potential water source. In addition, special core analysis shows a strong oil-wet nature of the reservoir rock. In the east section, sensitivity runs included infill development and variations in landing depth. It is noted that the production is not sensitive to landing zone because fracture geometry is primarily controlled by vertical stress profile. In the west section, sensitivity runs included refrac, infill drilling, and a greenfield development plan with variations on well spacing and completion design. The observation shows tighter well spacing or cluster spacing accelerates the oil production in early time, while yielding similar long term oil recovery and shows a combination of refrac and infill drilling yields a 21% incremental oil production beyond the base case. This study provides valuable information about the workflow to develop tight oil plays by describing a detailed case study. The result also sheds light on the optimized field development strategy for analogous fields.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Sedimentary Geology > Depositional Environment > Transitional Environment > Tidal Flat Environment (0.69)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock > Dolomite (0.62)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.46)
- Geophysics > Borehole Geophysics (0.69)
- Geophysics > Seismic Surveying (0.47)
- 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)
- (25 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization (1.00)
- Management > Asset and Portfolio Management > Field development optimization and planning (1.00)
Eliminating Losses in Permian Basin's Midland Basin Wells through Managed Pressure Drilling and Cementing
Thibodeaux, H.. (Chevron) | Williams, J.. (Chevron) | Duhe, N.. (Chevron) | Milazzo, J.. (Chevron) | Kvalo, M.. (Schlumberger) | Deplaude, O.. (Schlumberger) | Vargas, N.. (Schlumberger) | Hobin, J.. (Schlumberger) | Jesudas, J.. (Schlumberger) | Clements, J.. (Schlumberger)
Abstract The Permian basin has been one of the main drivers leading the recovery of recent drilling activity on U.S. land. It has been a focus for drilling activity that has targeted conventional reservoirs since the first well was drilled in 1925. Through the depletion of conventional reservoirs, fracture pressure in these zones has decreased due to the reduction in pore pressure. Some of these previously drilled reservoirs throughout the Permian Basin have been selected for the reinjection of produced water which has caused abnormal pore pressures to occur. The combination of having both loss and injection zones exposed in the same drilling interval has resulted in challenges for operators as they have to navigate the resulting mud weight windows of highly developed fields of the Midland and Delaware Basins. As development throughout the Permian basin continues, these mud weight windows will only become more difficult to manage. In one of Chevron's highly developed Midland Basin fields, managing the exposed injection and loss zones in the intermediate hole section proved to be challenging. This hole section had routinely experienced severe to complete losses upon entering the Upper Spraberry formation as a result of trying to manage higher pressures inflicted by the San Andres formation, a shallower injection zone. The mud weight could not be reduced to mitigate these losses without inducing an influx from the San Andres. Circulation could often not be reestablished upon entering the Spraberry formations which resulted in mud cap or blind drilling in order to reach section total depth (TD). These losses and overall wellbore conditions introduced higher risk and consequences in the form of well control events, wellbore instability, and mechanically or differentially sticking 9-5/8" casing prior to reaching planned set point. The immediate solution to isolate the wellbore problems was to implement a contingency liner, which comes at a premium and decreases drilling and completions efficiencies of the production hole section. Managed pressure drilling techniques were identified as a solution to simultaneously navigate a shallow injection zone and a deeper loss zone within the same hole section. The necessary equivalent mud weight profile was established through the reduction of MW and the addition of surface back pressure. This enabled a higher equivalent mud weight to be held at the shallow injection zone and a lower equivalent mud weight to be held across the loss zones. Additionally, managed pressure cementing techniques were used to achieve a similar pressure profile during cementing operations in order to increase the likelihood of maintaining returns while placing cement across the loss zones. Managed pressure drilling and cementing techniques implemented in this field contributed to the elimination of contingency liners and significant non-productive time in hole sections where both injection zones and loss zones were exposed. As laterals are extending beyond 10,000โ across the Permian Basin, the team has collectively proven the concept that the MPD system is part of an equipment package that can eliminate contingency liners and deliver the preferred sizes of production hole and production casing that is crucial to successfully reaching TD and efficiently placing hydraulic fracturing jobs at optimal rates.
- North America > United States > Texas (1.00)
- North America > United States > New Mexico (1.00)
- Geology > Geological Subdiscipline > Geomechanics (0.55)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.46)
- 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)
- (25 more...)
Over the past decade, microseismic monitoring, a technology developed for evaluating completions of wells drilled to produce hydrocarbons from unconventional reservoirs, has grown increasingly popular among oil and gas companies. This book discusses how to process microseismic data, what can and cannot be inferred from such data, and to what level of certainty this might be possible. The narrative of the book follows the passage of seismic waves: from a source triggered by hydraulic fracture stimulation, through hydrocarbon-bearing formations, towards motion sensors. The waves' characteristics encode the location of their source and its focal mechanism. The analysis of various approaches to harvesting the source-related information from microseismic records has singled out the accuracy of the velocity model, fully accounting for the strong elastic anisotropy of hydraulically fractured shales, as the most critical ingredient for obtaining precise source locations and interpretable moment tensors. The ray theory complemented by its modern extensions, paraxial and Frรฉchet ray tracing, provides the only practical means available today for building such models. The book is written for geophysicists interested in learning and applying advanced microseismic data-processing techniques.
- North America > United States > Texas (1.00)
- North America > United States > North Dakota (1.00)
- North America > United States > New Mexico (1.00)
- (11 more...)
- Overview (1.00)
- Summary/Review (0.87)
- Research Report > New Finding (0.45)
- Geology > Structural Geology > Tectonics > Plate Tectonics > Earthquake (1.00)
- Geology > Structural Geology > Fault (1.00)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play (1.00)
- (5 more...)
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Renewable > Geothermal > Geothermal Resource (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- North America > United States > Wyoming > Powder River Basin > Sussex Formation (0.99)
- North America > United States > Wyoming > Laramie Basin > Niobrara Formation (0.99)
- North America > United States > Utah > Paradox Basin > Greater Aneth Field > Aneth Field > Paradox Formation > Desert Creek Zone (0.99)
- (77 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
Geographically, the McElroy Field lays along the boundary between Crane and Upton counties in West Texas; geologically it is at the eastern edge of the Central Basin Platform of the Permian Basin (Figure 7.2). The field was discovered in 1926 and initially developed around the discovery well (Harris and Walker, 1990). The drilling of step-out wells and, as unlikely as it may seem, their hydraulic fracturing revealed the field to be much larger than originally anticipated, triggering several expansion phases from the 1930s to the early 1960s. Then, the infill drilling started with vertical wells in the early 1970s and with horizontal wells in the middle 2000s. Oil in the McElroy field is produced from the Upper Permian Grayburg formation, a dolostone deposited in shallow water. Most of the dolostone porosity is caused by its dolomitization, but vuggy and fracture porosity is present in portions of the field (Harris and Walker, 1990). The field is delimited by facies changes and accompanying deterioration of the reservoir quality. The in-situ stresses in the Grayburg formation were measured in its main payzone at depths 2,825 ft - 3,050 ft ( 861 m - 930 m). Among various attempted methods, minifracs provided the most reliable results (Avasthi et al., 1991; Nolen-Hoeksema et al., 1994), indicating the maximum horizontal stress to be oriented in a west-northwest direction (Table 7.2).
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock > Dolomite (0.74)
- North America > United States > Texas > Permian Basin > Midland Basin (0.99)
- North America > United States > Texas > Permian Basin > Central Basin > McElroy Field (0.99)
- North America > United States > New Mexico > Permian Basin > Delaware Basin > Grayburg Formation (0.99)
- (43 more...)
Abstract The Permian Basin in West Texas contains one of the thickest deposits of Permian rocks found anywhere in the world. The Embar-B lease located in southern Andrews County on the Central Basin Platform (a regional structural high in the Permian Basin) has been producing from the Leonardian Clearfork formation for over 70 years. The Clearfork formation is primarily a subtidal and intertidal carbonate rock characterized as moderate quality reservoir. Most Permian Basin fields have multiple stacked reservoirs with varying degrees of reservoir quality and there is typically a need in these maturing fields to increase reservoir contact. In 2009, a drilling campaign was launched in Embar-B with a focus on expanding the completion interval to include what was previously considered marginal pay in the deeper Wichita Albany formation. The Wichita Albany, also Leonardian in age, is composed mostly of marginal quality tidal flat rocks and is characterized by high fracture gradients and low permeability. These characteristics required an advancement in completion practices to achieve a successful stimulation. The combination of improved completions practices and an expanded target interval resulted in production double that of previous wells. This success has driven a need for an innovative development strategy and continued optimization of completion practices. Geomodeling, volumetrics, reservoir simulation, seismic attribute analysis and oil fingerprinting were all used for reservoir characterization and to determine an allocation method for commingled wells. This lead to the identification of several Clearfork/Wichita Albany locations with significant reserves potential. Re-evaluation of the completion strategy using a multidisciplinary approach indicated the need to reduce the number of perforation clusters, add a diversion mechanism, and develop multiple hydraulic fracturing designs based on reservoir quality and presence of natural fractures. Results from recent drilling programs have exceeded expectations bringing lease production up from 200 BOEPD in 2009 to a peak rate of 3153 BOEPD in 2015.
- North America > United States > New Mexico (1.00)
- North America > United States > Texas > Andrews County (0.66)
- Geology > Geological Subdiscipline (1.00)
- Geology > Sedimentary Geology > Depositional Environment > Transitional Environment > Tidal Flat Environment (0.88)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock (0.66)
- 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)
- (48 more...)
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (1.00)
- Well Completion > Completion Installation and Operations > Perforating (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- (2 more...)
Abstract San Andres carbonate reservoirs have long been known to have a high degree of reservoir heterogeneity and poor recovery efficiencies. Fractures are one of several causes of this heterogeneity. The heterogeneity causes unpredictability in water and CO2 flooding. However, the correct placement of horizontal wells can take advantage of this problem. An integrated reservoir characterization study of the Mabee field incorporating oriented core, Formation Microscanner (FMS) wireline logs, seismic time slices, production character, curvature analysis, and interference testing was used to predict fracture orientation and areas of highest fracture density. These fracture characteristics were then applied to determine horizontal well loca-tion and orientation. Fracture orientation was evaluated through the analysis of oriented core, FMS logs, and interference testing, indicating a fracture orientation of N70W. Analysis of the induced fractures in the oriented core indicates that the direction of maxi-mum horizontal compressive stress is N45E. High fracture density was delineated by curvature analysis, relative seismic amplitude, and areas of higher production. Areas with high curvature corre-spond to areas of high relative seismic amplitude and higher production. The data integration indicates that four areas have high fracture density. The synthesis of fracture orientation and density, along with the production character, indicates the optimal location and orientation of horizontal wells. Introduction Low-permeability San Andres reservoirs of the Central Basin Platform contain significant volumes of remaining oil. The Mabee San Andres field lies on the northeastern edge of the Central Basin Platform (Fig. 1) and is part of the San Andres/Grayburg Platform Carbonate play. Ref. 1 reported recovery efficiencies for secondary recovery of approximately 30% and an unrecovered resource of 2.6 billion stock-tank barrels of oil. The low recovery efficiency and still-remaining resource are due largely to the signif-icant amount of heterogeneity found in these reservoirs. San Andres Platform Carbonate reservoirs are highly hetero-geneous because of the depositional facies, diagenesis, and frac-turing. Ref. 2 described how grainstone bar depositional facies significantly affected the production character in Dune (Grayburg) reservoirs. Ref. 3 described how areas of postdepositional dia-genesis were the most highly productive in the Jordan (San Andres) reservoir. Additionally, fractures have been cited as contributing significant heterogeneity to San Andres/Grayburg reservoirs. Ref. 4 sited fractures in the Arrowhead (Grayburg) reservoir as the reason that tracers broke through in 2 days between a five-spot well pat-tern. Ref. 5 described the influence of fractures in the Keystone East (San Andres) reservoir. Ref. 6 described how fractures in the Chaveroo and Cato (San Andres) reservoirs influenced flow and storage volume. Ref. 7 depicted natural fractures as dominating the permeability character in zones of the Levelland (San Andres) reservoir. This heterogeneity causes preferential fluid flow and often-early breakthrough in waterfloods. It is also the likely cause of water loss previously unaccounted for in San Andres waterflood operations. Ref. 5 described a northeast preferential flow direction coincident with their interpreted direction of maximum horizontal compressive stress. Ref. 8 cited the Fullerton Clear Fork, Keystone Colby, and Means (San Andres/Grayburg) reservoirs as having east-west preferential flow directions. It is reasonable that this similar preferential flow direction in several fields and several formations is due to open fractures. Both the direction of open fractures and the location of densely spaced fractures influence how fractures affect production. In this study we combine geologic and engineering information including interference tests, oriented core, Formation Microscanner (FMS) logs, production data and curvature analysis to evaluate the direc-tion of open fractures and the areas where they may be more densely spaced.
- North America > United States > Texas > Andrews County (0.36)
- North America > United States > Texas > Crane County (0.28)
- North America > United States > New Mexico > Lea County (0.28)
- North America > United States > Texas > Travis County > Austin (0.15)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Carbonate Rock (0.48)
- Geophysics > Seismic Surveying (1.00)
- Geophysics > Borehole Geophysics (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)
- (42 more...)
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- (3 more...)