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Collaborating Authors
Results
Lessons Learned from a Case Study of Downhole Microseismic Mapping in the Southern Sichuan Shale Gas Play
Yue, Wenhan (Shale Gas Research Institute of PetroChina Southwest Oil&Gas Field Company) | Wang, Xinghao (Shale Gas Research Institute of PetroChina Southwest Oil&Gas Field Company) | Chen, Juan (Shale Gas Research Institute of PetroChina Southwest Oil&Gas Field Company) | Tang, Jie (Halliburton) | Zheng, Guangjie (Halliburton) | He, Long (Gepetto Oil Technology Group Co., Ltd)
Abstract A real-time downhole microseismic mapping technique was recently used in the southern Sichuan shale gas development. The case study presented illustrates this technique and analyzes the results, from the geological evaluation through the engineering solution, for a typical H24 pad fracturing.
- North America > United States > Texas (0.98)
- Asia (0.94)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.63)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play > Shale Gas Play (0.41)
- North America > United States > Wyoming > Green River Basin > Jonah Field (0.99)
- North America > Canada > British Columbia > Western Canada Sedimentary Basin > Horn River Basin (0.99)
- Asia > China > Sichuan > Sichuan Basin (0.99)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Management (1.00)
A Novel Technique on Microseismic - EDFM Fracture Modeling and Calibration for Complex Fractures in Unconventional Reservoirs
Mahmoud, Salah El din Ragab (ADNOC Upstream, Abu Dhabi, UAE) | Alshmakhy, Ahmed (ADNOC) | Leines-Artieda, Joseph Alexander (Sim Tech LLC, Texas, USA 77494) | Al-Jabery, Fatema (ADNOC Offshore) | Liu, Chuxi (The University of Texas at Austin, Texas, 78712) | AlHarthi, Amena (ADNOC Upstream) | Yu, Wei (Sim Tech LLC, Texas, USA 77494) | Fiallos-Torres, Mauricio Xavier (Sim Tech LLC, Texas, USA 77494) | Miao, Jijun (Sim Tech LLC, Texas, USA 77494) | Sepehrnoori, Kamy (ADNOC Upstream, Abu Dhabi, UAE)
Abstract Hydraulic fracture models are useful mechanisms to understand reservoir properties and performance in unconventional reservoirs. The inclusion of field measurements can further refine hydraulic fracture models by providing key information to optimize field development planning. Microseismic data remains as one of the most accessible types of field data, which can help understanding reservoir extension. Additionally, microseismic data is useful to assess well interference and extracting average hydraulic fracture geometry. However, an efficient method to extract cluster-based hydraulic fracture models from microseismic data is absent due to loss of spatial accuracy of current techniques when used in reservoir simulations. Moreover, accessibility to hydraulic fracture propagation simulators may add up to the challenge of producing reliable and fast estimates of fracture geometry. In this paper, our main objective is to efficiently reconstruct a hydraulic fracture model using microseismic data and combine it with a history matching workflow in order to optimize field development planning in a shale gas well. We created a fast and efficient cluster-based hydraulic fracture reconstruction tool, which uses microseismic events’ spatial distribution to create hydraulic fracture models represented by the embedded discrete fracture model (EDFM). Our workflow can include different sets of discrete fracture network (DFN) models, in order to assess their interactions with hydraulic fractures. We used two different DFN models: original DFN model and DFN represented by the activation of natural fractures during well stimulation. Finally, we calibrated our hydraulic fracture and DFN models to production data. We efficiently modeled the effective hydraulic fracture geometry that contributes to production by including spatial cut-off coefficients, which reduce fracture geometry in the history matching process. The results of this novel workflow produce not only efficiently calibrated hydraulic fracture models, but provides valuable insights regarding hydraulic fracture geometry and their interaction with natural fractures. Additionally, the inclusion of cut-off coefficients allows to model the effective contribution of hydraulic fractures after calibrating fracture geometry with production data.
- North America > United States > Texas (0.69)
- Asia > Middle East (0.69)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Fluid Characterization > Fluid modeling, equations of state (1.00)
Application of Multi-Information Fusion Fracture Modelling Based on Neural Network in Carbonate Dual: Medium Reservoir
Dan, Lingling (CNOOC Energy Technology-Drilling&Production Company) | Shi, Changlin (CNOOC Energy Technology-Drilling&Production Company) | Wen, Jiatao (China National Offshore Oil Corporation Limited) | Hu, Yunting (CNOOC Energy Technology-Drilling&Production Company) | Wei, Li (CNOOC Energy Technology-Drilling&Production Company) | Li, Yunxiu (CNOOC Energy Technology-Drilling&Production Company) | Zhang, Jian (CNOOC Energy Technology-Drilling&Production Company) | Tian, Panpan (CNOOC Energy Technology-Drilling&Production Company)
Abstract G oilfield in China is a dual medium oilfield dominated by carbonate reservoir, where faults and fractures are well developed. After G oilfield was put into production, water cut has rised quickly and oil production decreased rapidly. The heterogeneity of fracture development is very strong. Because of unclear understanding of the fracture distribution, oilfield development plan can not accurately identify risks and potentials accurately. As a result, production goals are not as expected. Due to limited core data and imaging logging data, conventional methods cannot characterize fracture information in this oilfield accurately and comprehensively. In order to solve the problems mentioned above, this paper makes full use of logging, geology, seismic and other data to carry out fine characterization of fracture with multi-information fusion fracture modeling based on neural network. Firstly, neural network technology is used to predict the fracture density curves of wells with conventional logging data. Secondly, combined the nonlinear fusion of multiple pre-stack seismic attributes including Tectonic Stress Field, P-Wave AVO and Seismic Discontinuity Detection based on neural network, the fracture density probability model is created to predict three-dimensional distribution of fractures. Thirdly, the fracture Intensity model is set up under the constraint of strict variation function analysis and fracture density probability model. Finally, fracture parameters are obtained according to core observation and imaging logging data, and the fracture network is established by geostatistics modeling method and coarsened equivalent into fracture property model. Blind well validation and dynamic validation are used to verify the validity of fracture model. Under the guidance of research results in this paper, the oilfield development plan is optimized and adjusted. It has also been proved that fracture characteristic of new wells is consistent with pre-drilling prediction result. Most areas with relatively high fracture development degree are corresponding to well groups with faster water cut rising rate. Against the backdrop of global oil economic downturn, fracture modeling technology studied in this paper provides strong technical guidance for oilfield development plan, therefore reducing oilfield development risks and maximizing economic benefits.
- Geology > Structural Geology (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Seismic Interpretation (0.72)
- Geophysics > Seismic Surveying > Seismic Processing > Seismic Migration (0.55)
- Asia > China > Xinjiang Uyghur Autonomous Region > Tarim Basin (0.99)
- Asia > China > South China Sea > Zhujiangkou Basin (0.99)
- Asia > China > Sichuan > Sichuan Basin > Puguang Field (0.99)
- North America > United States > Louisiana > China Field (0.97)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- (5 more...)
A Case Study Using 3D Hydraulic Fracturing Simulation of a Fully Integrated Subsurface 3D Reservoir Model in an Unconventional Tight Gas Reservoir
Izadi, Ghazal (Baker Hughes, a GE company) | Mahrooqi, Shabib (Petroleum Development Oman) | Shaibani, Mahmood (Petroleum Development Oman) | Dobroskok, Anastasia (Petroleum Development Oman) | Guises, Romain (Baker Hughes, a GE company) | Barton, Colleen (Baker Hughes, a GE company) | Ghadimipour, Amir (Baker Hughes, a GE company) | Randazzo, Santi (Baker Hughes, a GE company) | Bratovich, Matt (Baker Hughes, a GE company) | Tinnin, John (Baker Hughes, a GE company) | Walles, Frank (Baker Hughes, a GE company) | Khamatdinov, Rafael (Baker Hughes, a GE company) | Franquet, Javier (Baker Hughes, a GE company) | Perumalla, Satya (Baker Hughes, a GE company) | Freitag, Hans-Christian (Baker Hughes, a GE company)
Several wells have been drilled and stimulated in a tight gas field in Middle East, however, very few have been economic. Many wells encountered difficulties pumping the required treatment and a number of horizontal wells did not produce as expected. A fit-for-purpose integrated subsurface model coupling geophysical, petrophysical, and geomechanical models with fully 3D hydraulic fracture simulation modeling was carried out to provide the operational path forward to overcome these challenges. This study is a showcase of the applicability of our integrated approach to simulate fluid flow and proppant placement within complex, naturally fractured reservoirs where the interaction between induced fractures and natural fractures dominates hydraulic fracture propagation [Izadi et al. 2015; Cruz et al. 2016; Izadi et al. 2017; Izadi et al. 2018; Cruz et al. 2018]. Seismic data calibrated with rock physics analyses were used to delineate structural components and incorporate rock properties into the high-fidelity 3D subsurface model. High porosity zones and areas of high natural fracture intensity were identified with seismic acoustic impedance and geometric attributes. Reservoir properties of porosity, permeability and gas saturations vary across this field. Variations in geomechanical parameters correlate spatially with variations in porosity and permeability. This paper demonstrates a methodology to evaluate reservoir heterogeneities on hydraulic fractures propagation through fully 3D simulations at a planned well's location.
- North America > United States > Texas (0.69)
- Europe (0.69)
- South America > Argentina > Patagonia > Neuquén > Neuquen Basin > Vaca Muerta Shale Formation (0.99)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- (4 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Tight gas (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- (3 more...)
Integrated Geology Sweet Spot and Microseismic Monitor to Optimise Reservoir Stimulation - A Case for Shale Gas, China
Liu, Wei (BGP, CNPC, Chengdu University of technology) | He, Zhenhua (Chengdu University of technology) | Cao, Junxing (Chengdu University of technology) | Zhang, Jianjun (BGP, CNPC) | Xu, Gang (BGP, CNPC) | Wan, Xiaoping (BGP, CNPC) | Yu, Gang (BGP, CNPC)
Abstract Shale play, as one kind of non-conventional natural gas resource, has become the focus of domestic and overseas research in recent years. shale is pertained to be a reservoir with an ultralow porosity and permeability, its occurrence mode, accumulation pattern of natural gas, as well as development model are remarkably different conventional oil gas reservoirs, its development must be implemented by some special technique, e.g. horizontal drilling, drilling geologic steering, hydraulic fracturing, microseismic monitor, etc. Research shows, shale gas production depends on two factors, one is geological sweet spot factor, e.g. Total organic carbon, brittleness, core fluid pressure, micro-fractures, high quality shale thickness etc., the other is engineer technique factors, e.g. horizontal drilling, drilling geologic steering, hydraulic fracturing, microseismic monitor, fracturing schemes, etc. Single factor, sweet spots or engineering technique factor often not guarantee shale gas highly production, only when the most optimal combination of both, can achieve shale gas production maximization. How to integrate sweet spots and engineering technique to guide shale gas exploration and development? This is a serious question. This question involves to many fields, including geology and engineer sweet spots, horizontal well location deployment, drilling geologic steering, pre-fracturing warning and design, hydraulic fracturing design real-time adjustment, microseismic monitoring, etc., sweet spots results runs through the entire shale exploration and development. In this article, we will pay more attention to demonstrate that how to adjust the fracturing scheme and optimize the reservoir stimulation in real time by integrated geological sweet Spot and microseismic monitor.
- Asia > China (1.00)
- North America > United States > Texas (0.69)
- North America > United States > Texas > Fort Worth Basin > Barnett Shale Formation (0.99)
- Asia > China > Sichuan > Sichuan Basin (0.99)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Upper Marrat Formation (0.98)
- Asia > Middle East > Kuwait > Jahra Governorate > Arabian Basin > Widyan Basin > North Kuwait Jurassic (NKJ) Fields > Marrat Formation > Sargelu Formation (0.98)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
Abstract The permeability along a fracture is not constant, but varies with geometrical complexities such as pre-existing cracks. The spatial permeability changes affecting fluid pressure distributions can generate a sophisticated source mechanism potential to interpret measured seismicity complexity in the field. In this study, the relation between injection-induced seismicity and changes in fracture permeability during hydraulic fracturing stimulation of naturally fractured reservoirs is investigated numerically. In the model, the infinite homogeneous rock is assumed to be impermeable and elastic and a plane-strain fracture is embedded in it with distributed cracks. The fluid flow in the fracture is realized through over pressure generated by constant-rate injection. When the over-pressurized fluid enters these cracks, the pressure varying trend is changed and the injection pressure tends to increase, rather than decrease monotonically. Also, the slipping is temporarily stopped along the whole fracture. When the barrier to fluid flow is overcome, a most prominent pulse-type slip at a limited slip speed occurs along the pressurized region. The slip pulse can induce an injection pressure drop reflecting the decrease of the stress level near the rupture tip. In the meantime, the slip pulse acts as the source mechanisms for these microseismic events during the fracturing stimulation operations. It is found that the stress drop and slip rate decrease with rupture growth. In addition, the stopping phase and the accelerating duration of the slip patterns are two interesting features to estimate the source sizes of the rupture complexities generated by the forced fluid flow along a fracture.
- Geology > Geological Subdiscipline > Geomechanics (0.70)
- Geology > Structural Geology > Fault (0.48)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
Application of an Integrative New Technique on Modeling and Numerical Simulation for Fractured Reservoir Based on Unstructured Grid: A Case Study of JZS Buried Hill Reservoir
Lv, Zuobin (Tianjin Branch of CNOOC Ltd.) | Huo, Chunliang (Tianjin Branch of CNOOC Ltd.) | Ge, Lizhen (Tianjin Branch of CNOOC Ltd.) | Xu, Jing (Tianjin Branch of CNOOC Ltd.) | Zhu, Zhiqiang (Tianjin Branch of CNOOC Ltd.)
Abstract JZS oilfield is an offshore metamorphic rock fractured buried hill oilfield. It was put into development in July 2010. The overall production situation of the oilfield is good, but some problems have been exposed. The main performance is as follows: It is difficult to accurately characterize the heterogeneity of fracture space distribution; In the numerical simulation of fractured reservoir, it is impossible to accurately describe and predict the fracture flow of fluid channeling in corner point grid system. In order to solve the above problems, this study presents a new integrated fractured reservoir geological modeling and numerical simulation research method based on unstructured grid. There are three key aspects to this method. (1) The multi-scale (large, middle and small) discrete fracture system is established by combining outcrop measurement data with well point information and seismic attributes. On the basis of post-stack 3D seismic data, ants attributes are extracted, then the ant body results are transformed into large scale fractures; Using azimuth anisotropy attribute based on pre-stack inversion and combining the distribution orientation of large-scale fractures, the middle-scale fractures are established; According to the power law distribution relation between the cumulative frequency and the fracture length of large scale and small scale which based on outcrop observation, the imaging logging data and pre-stack inversion azimuth anisotropy attribute, small scale fractures are constructed by DFN technology.(2) For multi-scale fractures, the unstructured grid division technique is used to build a 3D model that conforms to the heterogeneity of dual media. In this study, a layered triangular prism grid generation technique is proposed. It is used to establish model of multi-scale fractures based on unstructured grid. Using large-scale fractures as a constraint, full 3D unstructured grid model is set up, and the discrete fracture model can accurately describe the fracture system and the coupling relationship between matrix and the fracture;(3)The triple-medium numerical simulation of the reservoir in the study area is carried out by using the automatic history fitting technology of ensemble kalman filter (EnKF). After several parameter adjustments, both the coincidence rate of the index and the fitting precision are higher than before. Multi-scale discrete fracture model based on the large-scale fractures discretization processing, equivalent medium processing to middle and small scale fractures, keeps the seepage characteristic of the large-scale discrete fractures model and ensures the calculation efficiency. The results show that the new method has obvious advantages in computing speed and that the fitting effect is closer to the actual production performance.
- Asia > China (0.95)
- North America > United States > Texas (0.66)
- Overview > Innovation (0.85)
- Research Report > New Finding (0.55)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Naturally-fractured reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation (1.00)
- (2 more...)
Abstract Hydraulic fracturing is carried out in most shale gas fields to enhance reservoir permeability. Thousands of microseismic events are observed with geophone arrays during fracking stages. Microseismic hypocenter distributions are essential information to delineate stimulated reservoir volume (SRV), and there are some useful automatic processing tools to get hypocenter locations. However, recorded seismograms contain noise and complex phases that cause ambiguity in the data processing. In addition, the velocity model selected has a great influence on the accuracy of the hypocenter information. In this research, to enhance the accuracy of microseismic event hypocenter locations, we picked P and S phases using an array seismogram volume (ASV). The ASV consists of shot gathers and receiver gathers of selected events and receivers. The events should be limited to those that have enough waveform similarity. Once we pick an onset time of a single trace in the ASV, the picked seed trace is compared with neighboring traces using cross correlation; most of the onset times in the ASV are picked automatically. Because the process requires picking of single traces, we call this procedure semi-auto picking. This semi-auto picking tool can reduce the time needed for manual picking and the process is efficient and provides high-quality results. Shale sediment are frequently characterized by anisotropic parameters. The sediments in Barnett, our study area, also show anisotropy. Therefore, an accurate velocity model is required to achieve precise microseismic event analysis. A tilted layer orthorhombic velocity model was adopted in this study. P-wave sonic and gamma ray logs were available for a reference well located close to the study area. The 3D seismic survey interpretation provided a tilted layer angle. The principal horizontal stress direction was provided by a previous study in Barnett. Using this geoscience information as constraints, a number of optimized parameters could be reduced. Seven Thomsen parameters and the Vp/Vs ratio of the defined layers were optimized using perforation shots. A grid search location approach was applied to locate 932 events during a single fracking stage. To obtain final locations, the following objective functions were combined: (1) P, Sh, and Sv travel time misfits; (2) travel time differences between receivers; (3) travel time differences between different wave phases; (4) travel time differences between microseismic events and master events (perforation shots); (5) P phase polarization; and (6) P phase polarization differences between microseismic and master events. Spatio-temporal behavior of the located event cloud was investigated using R-T plot analysis. The SRV was observed to grow with the injection volume in this stage and the effective fracture thickness was almost 10 mm after treatment.
- Geology > Geological Subdiscipline > Geomechanics (0.48)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.46)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
Abstract Hydraulic fracture calibration in an unconventional environment is a complex process and is inconsistently practiced. Automated calibration methods are not effective or efficient in accounting for the heterogeneity and variation of constraining parameters. However, it is important to build a consistent methodology to calibrate hydraulic fractures incorporating the observed data. This paper covers the systematic "Seismic to Simulation" workflow for unconventional reservoirs to constrain a hydraulic fracture model to obtain a calibrated result. For the hydraulic fracture calibration, injection fall-off tests, sonic logs and image logs are commonly used as the primary inputs to calibrate the geomechanical model. A new workflow is developed to be used consistently incorporating the learnings from the traditional fracture calibration methods. Impact of high stress barriers and height and pinchouts of fractures are incorporated in a geomechanical-flow model. Simultaneous matching of the observed net pressure trend, incorporating the effect of reservoir laminations on fracture height growth is made using a complex fracture model. The effect of the natural fracture networks (NFN) on pressure losses and proppant transport is also accounted for in the fracture geometry. Further, hydraulic fracture geometry is calibrated using the microseismic data. The production behavior was validated using numerical simulation for production history matching. A case study from the Permian basin is considered for the paper. The fracture geometry and footprint obtained using the calibration workflow match very closely the observed surface and downhole measurements. We constrained the model by matching the net pressures and achieved simulated production to match within 10% error compared to the actual oil and gas production. The fracture geometry was calibrated using microseismic data and controlled by incorporating the effect of weak interfaces and laminations. This workflow successfully demonstrates hydraulic fracture model calibration using pressure matching, microseismic data and production history matching. Systematically and consistently using this workflow provides solutions for infill well planning and well spacing for asset optimization. This paper explains a systematic fracture calibration procedure that can be easily adopted by the operators to obtain reliable results in unconventional wells. The effect of reservoir laminations and impact of natural fracture in calibrating the fracture geometry and fracture pressure trend is uniquely demonstrated in this study.
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (1.00)
- Geology > Geological Subdiscipline > Geomechanics (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)
- (22 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 Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Fluid Characterization > Fluid modeling, equations of state (1.00)
A Geoengineering Long March to Success: An Overview of the Development of Keshen Gas Field in Kucha Foreland Basin
Jiang, Tongwen (PetroChina) | Xian, Chenggang (China Petroleum University) | Yang, Xiangtong (PetroChina) | Huang, Yongjie (Schlumberger) | Zhang, Yang (PetroChina) | Pan, Yuanwei (Schlumberger)
Abstract Significant challenges meeting together make Keshen gas field in Kucha foreland basin become unique from geosciences, engineering and economics points of view. These challenges generally link to harsh geography, super deep (>6500m TVD), thick conglomerates (up to 3000m), heterogeneous salt-gypsum laminations (up to 2000m), complex thrust-nappe structure, HTHP, and ultra-tight (matrix permeability < 0.1 md). This paper gives a comprehensive review how the geoengineering Long March assists to successfully develop this field. A geoengineering team was established to persistently attack on this world-class championship with high-level planning since 2012. Specific research and development of engineering technologies and solutions for data acquisition, drilling, completion, stimulation, testing and production and studies were taking place in parallel. To ensure seamless integration from geosciences and engineering to operation, a five-year geoengineering study was proactively and progressively executed which includes four major steps with respective objectives including 1) understanding fluid distribution and producibility, 2) well production breakthrough and enhancement, 3) optimization of well stimulation and economics, and 4) optimization of field management including surprising sanding problem. It was recognized three elements and their interactions are critical for production enhancement which are natural fracture (NF) characteristics, production controlling mechanism, and stimulation optimization under super deep, HPHT and extremely high stress conditions. The bottleneck for study was poor seismic quality due to super depth, pre-salt, and complex thrust-nappe structures. Hence the team established comprehensive methodologies with iterative improvements to overcome this bottleneck. Using regional structural geology, outcrops, cores, images and logs as inputs, structure restoration and geomechanics simulators were combined to perform structure restoration, paleo-stresses, and in-situ stresses and eventually 3D NF prediction. To understand production mechanism, analysis of geological and geomechanical factors, NF and stress relationships, single parameter and multiple variables, and transient and production performance were integrated. Big core studies were conducted to understand fracability, NF and hydraulic fracture (HF) interactions, and selections of HF fluids. Based upon, a stimulation optimization approach was implemented which included engineered completion designs, HF modeling and parametric studies, post-frac analysis and optimization, and time effects through high-resolution coupled geomechanics and reservoir simulation. All efforts with evolving knowledge were eventually developed as an interactive expert system to guide systematic stimulation optimization, sanding management and development optimization. With increasing understanding of reservoir, and implementing innovative solutions, it was enabled to drill wells at optimal locations with less time, simplified well configuration, and less constraints on stimulation and production operations. By 2017, well construction time was reduced by half, natural productivity of wells was doubled, productivity after stimulation was tripled, and overall cost of wells was largely reduced. The success achieved would boost confidence and lighten on development of other challenging fields.
- Asia > China > Xinjiang Uyghur Autonomous Region > Tarim Basin > Keshen Field (0.99)
- Asia > Thailand > Gulf of Thailand > Western Basin (0.91)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > HP/HT reservoirs (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- (3 more...)