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Collaborating Authors
Results
Abstract Numerical Rate Transient Analysis (RTA) and production forecast models for unconventional reservoirs usually rely on single well analysis, with relatively simple assumptions regarding the geometry of the hydraulic fractures (identical and uniformly distributed). In this paper, we describe a transient numerical model for deviated well trajectories intercepting a complex distribution of fractures. The model can incorporate multiple wells and account for various modes of interference, including fracture hits. This approach enables the initialization and calibration of new types of transient models, which are directly compatible with the results of advanced completion diagnostics. In the proposed approach, the near-well region is discretized with a fully automated unstructured grid, rigorously constrained to the fractures. The algorithm accounts for independent fracture properties (ex: azimuth, half length, thickness, offset…). Hydraulic fractures originating from a given well can intercept one or several other wellbores or existing fractures. Complex transient interference modes between fractures, as well as fracture-driven communications between wells can then be analyzed. The geometrical grid resulting from complex fracture distributions may contain a very large number of cells. To overcome this issue, a new "aggregation" scheme is proposed, which reduces the size of the computational system and considerably accelerates the calculations. The model is validated in single and multiwell configurations, with different fracture distributions and interference modes. The impact of wells interference on the RTA interpretation and the production forecast is accounted for. This model is also tested for multiphase simulation - including phase changes. The proposed aggregation scheme results in a reduction of the computational system size by up to 2 orders of magnitude, leading to much faster direct simulations. Comparisons of the log-log derivatives show that the different flow regimes are accurately captured with the new scheme, even at very early-time. Because the aggregation scheme proceeds on zones with similar pressure behavior, there is no need for pseudo-relative permeability derivations, and the results remain accurate for multiphase flow and pressure-dependent petrophysical properties. This model provides a new solution for transient, nonlinear numerical simulation of fractured horizontal wells with complex geometries. The model can be applied to numerical Rate or Pressure Transient Analysis in unconventional reservoirs, without being limited to a geometrical element of symmetry.
- North America (0.29)
- South America (0.28)
- 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...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- (3 more...)
Modeling Transient Flow Behavior of Off-Center Fractured Well with Multiple Fractures in Radial Composite Gas Reservoirs
Xu, Youjie (Chongqing University of Science and Technology (Corresponding author)) | Zuping, Xiang (Chongqing University of Science and Technology) | Yu, Mengnan (School of Petroleum Engineering, Chongqing University of Science and Technology)
Summary Vertical hydraulic fracturing is widely used to develop low-permeability gas reservoirs. Uneven distribution of formation permeability and stress leads to multiple-wing hydraulic fractures with different lengths, which results in the wellbore not being the center of the circular stimulated reservoir volume (SRV) region. Therefore, to simulate the wellbore pressure of this phenomenon, a semianalytical model of the off-center multiwing fractured well in radial composite gas reservoirs is presented and the corresponding solution method is shown. The model is verified with the numerical solution, and eight flow regimes can be distinguished under the ideal case, which includes bilinear flow, fracture interference, linear flow, radial flow of inner region, transition flow of inner region, and radial flow of inner region. Compared with the previous model in which the well is at the center of radial composite gas reservoirs, in this paper we present an obvious “step” after the inner region radial flow regime, which is related to the off-center distance and radius of the inner region. In addition, the effects of some important parameters (such as off-center distance, permeability mobility, inner region radius, and fracture distribution) on typical curves are discussed. Finally, field well testing data are used to verify the accuracy of the model.
- North America > United States > Oklahoma > Anadarko Basin > M Formation (0.99)
- Asia > China > Shanxi > Ordos Basin (0.99)
- Asia > China > Shaanxi > Ordos Basin (0.99)
- (2 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- (3 more...)
A Two-Phase Type-Curve Method with Fracture Damage Effects for Hydraulically Fractured Reservoirs
Zhang, Fengyuan (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum-Beijing, Beijing, China) | Pan, Yang (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum-Beijing, Beijing, China) | Rui, Zhenhua (National Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum-Beijing, Beijing, China) | Emami-Meybodi, Hamid (Department of Energy and Mineral Engineering and EMS Energy Institute, The Pennsylvania State University, State College, Pennsylvania, USA) | Yang, Chia-Hsin (Department of Energy and Mineral Engineering and EMS Energy Institute, The Pennsylvania State University, State College, Pennsylvania, USA) | Wang, Ruiqi (Department of Oil Field Development, Research Institute of Petroleum Exploration & Development, Beijing, China) | Zhang, Wei (Department of Geoscience, University of Calgary, Calgary, Alberta, Canada)
Abstract Type-curve analysis on flowback and production data is a powerful tool in characterizing hydraulic fractures (HF) and reservoir properties. In order to evaluate HF characteristics and their dynamics for multi-fractured horizontal wells (MFHWs) in hydrocarbon reservoirs, we provide a novel type-curve method and an iterative workflow. The type curve incorporates the fracture damage effect, which is characterized by choked-fracture skin factor, into the two-phase flow in HF and matrix domains. The type-curve method can be applied to inversely estimate choked-fracture skin factor, fracture pore-volume, fracture premeability, and fracture permeability modulus through the analysis of two-phase production data. By introducing the new dimensionless parameters, the non-uniqueness problem of the proposed semianalytical method is significantly reduced by incorporating the complexity of fracture dynamics into one set of curves. The proposed type curve's accuracy is examined by numerical simulations of a shale gas and shale oil reservoir. The validation results demonstrate the good match of analytical type curves and numerical data plots and confirms the accuracy of the proposed approach in estimating the static and dynamic fracture properties. The flexibility and robustness of the proposed method are illustrated using the field example from a shale oil MFHW. The interpreted results from the flowback analysis of the field example offers a quantitative insight of fracture properties and dynamics.
- North America > United States (1.00)
- North America > Canada > Alberta (0.28)
- Geology > Geological Subdiscipline (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.90)
- North America > United States > Gulf of Mexico > Central GOM > West Gulf Coast Tertiary Basin > Walker Ridge > Block 628 > Julia Field (0.99)
- North America > United States > Gulf of Mexico > Central GOM > West Gulf Coast Tertiary Basin > Walker Ridge > Block 627 > Julia Field (0.99)
- North America > United States > Gulf of Mexico > Central GOM > West Gulf Coast Tertiary Basin > Walker Ridge > Block 584 > Julia Field (0.99)
- (2 more...)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- (8 more...)
A Real-Time Inversion Approach for Fluid-Flow Fractures in Unconventional Stimulated Reservoirs
Sheng, Guanglong (Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas, Yangtze University / School of Petroleum Engineering, Yangtze University) | Zhao, Hui (Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas, Yangtze University / School of Petroleum Engineering, Yangtze University (Corresponding author)) | Huang, Luoyi (Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas, Yangtze University / School of Petroleum Engineering, Yangtze University (Corresponding author)) | Huang, Hao (Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas, Yangtze University / School of Petroleum Engineering, Yangtze University) | Liu, Jinghua (Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas, Yangtze University / School of Petroleum Engineering, Yangtze University)
Summary Fluid-flow fractures, through which fluids can move under pressure, make a more significant contribution to increasing production than do microseismic and propagation fractures. An accurate description of the distribution of fluid-flow fractures is the basis for evaluating hydraulic fracturing and oil/gas recovery. In this study, a real-time inversion approach for fluid-flow fractures was proposed, and the complex fluid-flow fracture morphology was obtained in real time by updating the data of the fracturing construction curve. First, a dynamic permeability model was proposed to describe the filtration rate of the fracturing fluid during hydraulic fracturing. Combined with the point source function, the flowing bottomhole pressure (pwf) can be quickly calculated based on the fracture morphology and displacement of the fracturing fluid. The variance of pwf and bottomhole pressure (pwb) obtained by pump pressure were used as an objective function, and the length of fluid-flow fractures and fracture morphology were used as fitting parameters. The length of the fluid-flow fractures was updated with the simultaneous perturbation stochastic approximation (SPSA) to achieve a rough fitting of the bottomhole pressure. On this basis, a probability function was used to constrain the randomness of the fractures, and the fracture morphology with a fixed fracture length was continuously simulated and finely matched. Finally, a complex fluid-flow fracture morphology was obtained. The method was used to analyze the fluid-flow fracture morphology of multifractured horizontal wells in shale reservoirs, and the fitting rate of the fracturing construction curve was more than 95%. The results show that the total length of the fluid-flow fractures in one stage in naturally fractured reservoirs was approximately 629 m, and those in homogeneous reservoirs and high-stress difference reservoirs were 564 m and 532 m, respectively. The length of fluid-flow fractures with “grooves” in the fracturing construction curve was longer than the length of fluid-flow fractures with “bulges.” The effectively stimulated reservoir area with fluid-flow fractures was only approximately 28–51% of the stimulated reservoir area with microseismic fractures.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.49)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- North America > United States > Texas > Permian Basin > Midland Basin (0.99)
- North America > United States > Texas > Fort Worth Basin > Barnett Shale Formation (0.99)
- (3 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- (5 more...)
Production Data Analysis of Shale Oil Reservoir Using the Dynamic Drainage Pore Volume Concept: Lessons-Learned from Well-To-Well Fracture Driven Interaction in Lucaogou Shale Formation
Pan, Yuewei (1. PetroChina Exploration & Production Company, Beijing, China) | Qin, Jianhua (2. Research Institute of Petroleum Exploration & Development, Beijing, China) | Zhang, Jing (Xinjiang OilField Company, Karamay, Xinjiang, China) | Shang, Jianlin (Xinjiang OilField Company, Karamay, Xinjiang, China) | Ma, Wei (Xinjiang OilField Company, Karamay, Xinjiang, China)
Abstract Many pilot researches consider production gains or losses in parent/child wells in short-term thereby determining the optimal completion parameters (eg. well spacing, stage spacing). Long-term recovery varies from negative-to-positive during the post-frac-hit evaluation based on the magnitude of the pressure sink and the distance of parent/child wells. However, quantitatively analyzing frac-hits impact remains unsolved. This paper presents a novel workflow combining RTA diagnostic plots and the prediction of dynamic drainage pore volume (DDPV) to analyze the frequent well/well fracture-driven interaction (FDI) (commonly referred to as frac-hits) in the Lucaogou shale formation, Junggar Basin. According to the published knowledge, different strategies have been employed in Lucaogou formation to minimize the negative effect and to avoid the parent/child wells (e.g cube-development). Thus, optimizing stage, cluster and well spacing in well-pad zipper-frac development is in necessity. This paper first reviews the frac-hit mechanisms in both parent/child wells and well-pad zipper-frac development. We then characterize, quantify and rank the historical frac-hit events in Lucaogou formation based on the documented data. With the prediction of DDPV using numerical integration/differentiation assisted by diagnostic plots and specialized plots in RTA (eg. flowing material balance plot, square-root-of-time diagnostic plot), the pressure sink front can be acquired. The accuracy of DDPV forecast is validated using a synthetic case study. We further apply it to three field case studies to demonstrate the versatility and applicability of the proposed workflow. The successful applications suggest that the proposed workflow is an alternative to making field-development decisions, minimizing the negative impacts of frac-hits and thus freeing the cashflows. The outcomes are mainly but not limited to: 1) the common early departures from linear flow regime are in good alignment with the DDPV forecasts in both parent/child and well-pad development scenarios; 2) A competition of the per-well DDPV might be triggered during frac-hits in parent/child well and 3) long-term recovery in well-pad development with a tighter well-spacing might be boosted with a smaller per-well DDPV and DOI.
- North America > United States > Texas (1.00)
- Asia > China (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Geology > Geological Subdiscipline (1.00)
- North America > United States > Texas > Haynesville Shale Formation (0.99)
- North America > United States > Louisiana > Haynesville Shale Formation (0.99)
- North America > United States > Arkansas > Haynesville Shale Formation (0.99)
- (3 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- (8 more...)
A Review of Hydraulic Fracturing and Latest Developments in Unconventional Reservoirs
Temizel, Cenk (Saudi Aramco) | Canbaz, Celal Hakan (Ege University) | Palabiyik, Yildiray (ITU) | Hosgor, Fatma Bahar (Petroleum Experts LLC) | Atayev, Hakmyrat (ITU) | Ozyurtkan, Mustafa Hakan (ITU) | Aydin, Hakki (METU) | Yurukcu, Mesut (UTPB) | Boppana, Narendra (UTPB)
Abstract Hydraulic fracturing is a widely accepted and applied stimulation method in the unconventional oil and gas industry. With the increasing attention to unconventional reservoirs, hydraulic fracturing technologies have developed and improved more in the last few years. This study explores all applications of hydraulic fracturing methods to a great extent. It can be used as a guideline study, covering all the procedures and collected data for conventional reservoirs by considering the limited parameters of unconventional reservoirs. This paper intends to be a reference article containing all the aspects of the hydraulic fracturing method. A comprehensive study has been created by having a wide scope of examinations from the applied mechanisms to the technological materials conveyed from the different industries to utilize this technique efficiently. Furthermore, this study analyses the method, worldwide applications, advantages and disadvantages, and comparisons in different unconventional reservoirs. Various case studies that examine the challenges and pros & cons of hydraulic fracturing are included. Hydraulic fracturing is a promising stimulation technique that has been widely applied worldwide. It is challenging due to the tight and nanoporous nature, low permeability, complex geological structure, and in-situ stress field in unconventional reservoirs. Consequently, economic conditions and various parameters should be analyzed individually in each case for efficient applications. Therefore, this study provides the primary parameters and elaborate analysis of the techniques applied for a successful stimulation under SPECIFIC circumstances and provides a full spectrum of information needed for unconventional field developments. All the results are evaluated and detailed for each field case by providing the principles of applying hydraulic fracturing technologies. Many literature reviews provide different examples of hydraulic fraction methods; however, no study covers and links up both the main parameters and learnings from real cases worldwide. This study will fill this gap and illuminate the application of the hydraulic fracturing method.
- North America > United States > Texas (1.00)
- North America > United States > North Dakota (1.00)
- Europe (1.00)
- (4 more...)
- Research Report > Experimental Study (0.67)
- Research Report > New Finding (0.45)
- Overview > Innovation (0.45)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play > Shale Gas Play (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.94)
- Geophysics > Seismic Surveying > Passive Seismic Surveying > Microseismic Surveying (1.00)
- Geophysics > Borehole Geophysics (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Materials > Chemicals > Commodity Chemicals > Petrochemicals (0.67)
- Well Drilling > Wellbore Design > Wellbore integrity (1.00)
- Well Drilling > Drilling Operations > Directional drilling (1.00)
- Well Completion > Hydraulic Fracturing > Multistage fracturing (1.00)
- (20 more...)
Summary We propose a novel method for estimating average fracture compressibility during flowback process and apply it to flowback data from 10 multifractured horizontal wells completed in Woodford (WF) and Meramec (MM) formations. We conduct complementary diagnostic flow-regime analyses and calculate by combining a flowing-material-balance (FMB) equation with pressure-normalized-rate (PNR)-decline analysis. Flowback data of these wells show up to 2 weeks of single-phase water production followed by hydrocarbon breakthrough. Plots of water-rate-normalized pressure and its derivative show pronounced unit slopes, suggesting boundary-dominated flow (BDF) of water in fractures during single-phase flow. Water PNR decline curves follow a harmonic trend during single-phase- and multiphase-flow periods. Ultimate water production from the forecasted harmonic trend gives an estimate of initial fracture volume. The estimates for these wells are verified by comparing them with the ones from the Aguilera (1999) type curves for natural fractures and experimental data. The results show that our estimates (4 to 22×10psi) are close to the lower limit of the values estimated by previous studies, which can be explained by the presence of proppants in hydraulic fractures.
- North America > United States > Texas (1.00)
- North America > Canada > Alberta (0.68)
- Europe (0.67)
- Research Report > New Finding (0.67)
- Research Report > Experimental Study (0.66)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play (0.68)
- Geology > Mineral > Silicate (0.67)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.31)
- North America > United States > Texas > Fort Worth Basin > Barnett Shale Formation (0.99)
- North America > United States > Texas > Anadarko Basin (0.99)
- North America > United States > Oklahoma > Woodford Shale Formation (0.99)
- (10 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale oil (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- (7 more...)
Rigorous Estimation of the Initial Conditions of Flowback Using a Coupled Hydraulic-Fracture/Dynamic-Drainage-Area Leakoff Model Constrained by Laboratory Geomechanical Data
Zhang, Zhenzihao (University of Calgary) | Clarkson, Christopher (University of Calgary) | Williams-Kovacs, Jesse D. (University of Calgary and Sproule Associates) | Yuan, Bin (University of Calgary) | Ghanizadeh, Amin (University of Calgary)
Summary The application of rate‐transient‐analysis (RTA) concepts to flowback data gathered from multifractured horizontal wells (MFHWs) completed in tight/shale reservoirs has recently been proposed as an independent method for quantitatively evaluating hydraulic‐fracture volume/conductivity. However, the initial fluid pressures and saturation in the fracture network and adjacent reservoir matrix are generally unknown at the start of flowback, creating significant uncertainty in the quantitative analysis of flowback data. In this study, we present a semianalytical flow model, coupled with a hydraulic‐fracture (fracture) model and constrained with laboratory‐based geomechanical data, for evaluating the initial conditions of flowback. In previous work, a semianalytical model based on the dynamic‐drainage‐area (DDA) concept was used to simulate water‐based fluid leakoff from an MFHW into a tight oil reservoir (Montney Formation, western Canada), with minimal mobile water, during and after fracturing operations. The model assumed that each fracturing stage can be represented by a primary hydraulic fracture (PHF) containing the majority of the proppant, and an adjacent nonstimulated reservoir (NSR) or enhanced fracture region (EFR), which is an area of elevated permeability in the reservoir caused by the stimulation treatment. Each region was represented by a single‐porosity system. The DDA propagation speed within the PHF during the stimulation treatment was constrained through using a simple analytical fracture model. Although this approach was considered novel, several improvements and additional laboratory constraints were considered necessary to yield more accurate predictions of initial flowback conditions. In the current work, the modeling approach described previously was improved by representing the EFR with a dual‐porosity system; fully coupling the fracture model (used for PHF creation and propagation) with the DDA model for fluid‐leakoff simulation into the EFR and adding a proppant‐transport model; and modeling the shut‐in period. Finally, to ensure that model geomechanics were properly constrained, a comprehensive suite of previously gathered laboratory data was used. Laboratory‐derived propped (PHF) and unpropped (EFR) fracture‐permeability/conductivity data as a function of pore pressure, as well as fracture‐compressibility data, were used as constraints for the model. It should be noted that our model assumes that fracture closure has no effect on the pressure/saturation of the PHF/EFR/matrix. The improved model was reapplied to the tight oil field case and yielded more realistic estimates of initial flowback conditions, enabling more confident history matching of flowback data. The results of this study will be important to those petroleum engineers interested in quantitative analysis of flowback data to accurately obtain fracture properties by ensuring proper model creation.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.34)
- North America > Canada > British Columbia > Western Canada Sedimentary Basin > Greater Peace River High Basin > Upper Montney Formation (0.99)
- North America > Canada > British Columbia > Western Canada Sedimentary Basin > Alberta Basin > Montney Formation (0.99)
- North America > Canada > Alberta > Western Canada Sedimentary Basin > Alberta Basin > Montney Formation (0.99)
- Well Completion > Hydraulic Fracturing > Multistage fracturing (1.00)
- Well Completion > Hydraulic Fracturing > Fracturing materials (fluids, proppant) (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- (6 more...)
A Novel Semi-Analytical Model for Highly Deviated Wells in Fractured-Vuggy Carbonate Gas Reservoirs
Wang, Kongjie (Changqing Downhole Technology Company, CNPC Chuanqing Drilling Engineering Co., Ltd.) | Li, Zhiping (School of Energy Resources, China University of Geosciences, Beijing, China) | Wang, Lian (School of Energy Resources, China University of Geosciences, Beijing, China) | Shi, Hua (State Engineering Laboratory of Low-permeability Oil and Gas Field Exploration and Development, Xi'an, Shanxi, China, Oil and Gas Technology Research Institution of Petrochina Changqing Company, Xi'an, Shanxi, China) | Adenutsi, Caspar Daniel (Council for Scientific and Industrial Research-Institute of Industrial Research, Ghana) | Wu, Junda (School of Energy Resources, China University of Geosciences, Beijing, China) | Wang, Chao (Schlumberger, Binhai New District, Tianjin, China)
Abstract The study of pressure transient behavior in fractured-vuggy reservoirs has recently received considerable attention because a number of such reservoirs have been found worldwide with significant oil and gas production and reserves. In recent years, the use of highly deviated wells (HDW) is considered an effective means for developing this type of gas reservoir. However, in many fractured-vuggy reservoirs unexpected high gas production have been observed which cannot be identified with pressure transient models of horizontal well with pseudo state triple-porosity interporosity flow. This paper presents a semi-analytical model that analyzed the pressure transient behavior of HDW in triple-porosity continuum medium which consist of fractures, vugs and matrix. Introducing pseudo-pressure, Laplace transformation and Fourier transformation were employed to establish a point source and line source pseudo-pressure solutions in Laplace space. Then the pseudo-pressure transient curve was got by numerical inversion. Furthermore, the flow characteristics were analyzed thoroughly by examining the curve which is mainly affected by inclination angle of HDW and interporosity flow coefficients between different pore media. Sensitivity analysis on the pressure transient behavior was performed by varying some important parameters such as the inclination angle, fracture storativity ratio and interporosity flow coefficients. Finally, a field case was successfully used to show the application of the presented semi-analytical model. With its high efficiency, this approach will serve as a reliable tool to evaluate the pressure behavior of HDW in fractured-vuggy carbonate gas reservoirs.
- Asia > China (1.00)
- Europe (0.68)
- North America > United States > Texas (0.28)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Carbonate reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- (7 more...)
Case Studies of Integrated Flowback Analysis: Examples from the Montney and Duvernay Formations
Clarkson, Christopher R. (University of Calgary) | Williams-Kovacs, Jesse (University of Calgary and Sproule Associated Limited) | Zhang, Zhenzihao (University of Calgary) | Yuan, Bin (University of Calgary) | Ghanizadeh, Amin (University of Calgary) | Hamdi, Hamidreza (University of Calgary) | Islam, Arshad (Baytex Energy Corp.)
Abstract Recently it has been demonstrated that rate-transient analysis (RTA) performed on flowback data frommulti-fractured horizontal wells (MFHWs) can provide timely estimates of hydraulic fracture properties. This information can be used to inform stimulation treatment design on upcoming wells as well as other important operational and development decisions. However, RTA of flowback data may be complicated by rapidly changing operating conditions, dynamic hydraulic fracture properties and multi-phase flow in the fractures, complex fracture geometry, and variable fracture and reservoir properties along the MFHW, among other factors. While some constraints on RTA model assumptions may be applied through a carefully-designed surveillance and testing program in the field (e.g. to constrain fracture geometry), still others require laboratory measurements. In this work, an integrated flowback RTA workflow, designed to reduce uncertainty in derived hydraulic fracture properties, is demonstrated using flowback data from MFHWs producing black oil from low-permeability reservoirs in the Montney and Duvernay formations. The workflow includes rigorous flow-regime identification used for RTA model selection, straight-line analysis (SLA) to provide initial estimates of hydraulic fracture properties, and model history matching of flowback data to refine hydraulic fracture property estimates. The model history matching is performed using a recently-introduced semi-analytical, dual-porosity, dynamic drainage area (DP-DDA) model that incorporates primary (propped) hydraulic fractures (PHF) as well as a dual-porosity enhanced fracture region (EFR) with an unpropped (secondary) fracture network. Inclusion of both the PHF and EFR components addresses the need to incorporate both propped and unpropped fractures and fracture complexity in the modeling. The DP-DDA model is constrained using estimates of propped fracture conductivity and unpropped fracture permeability (measured as a function of stress), and unpropped fracture compressibility values, obtained in the laboratory for Montney and Duvernay core samples. Use of these critical laboratory data serves to improve the confidencein the modeling results. The case studies provided herein demonstrate a rigorous workflow for obtaining more confident hydraulic fracture property estimates from flowback data through the application of RTA techniques constrained by both field and laboratory data.
- North America > United States (1.00)
- North America > Canada > Alberta (1.00)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- North America > United States > New Mexico > Permian Basin > Wolfcamp Formation (0.99)
- North America > Canada > Alberta > Western Canada Sedimentary Basin > Alberta Basin > Duvernay Field > Duvernay Formation > Acl Duv 13-12-57-13 Well (0.94)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- (4 more...)