The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
- Data Science & Engineering Analytics
The SPE has split the former "Management & Information" technical discipline into two new technical discplines:
|Theme||Visible||Selectable||Appearance||Zoom Range (now: 0)|
Abstract Representation learning is a technique for transforming high-dimensional data into lower-dimensional representations that capture meaningful patterns or structures in the data. Uniform manifold approximation and projection (UMAP) enables representation learning that uses a combination of nearest neighbor search and stochastic gradient descent in the low-dimensional graph-based representation to preserve local structure and global distances present in high-dimensional data. We introduce a new technique in representation learning, where high-dimensional data is transformed into a lower-dimensional, graph-based representation using UMAP. Our method, which combines nearest neighbor search and stochastic gradient descent, effectively captures meaningful patterns and structures in the data, preserving local and global distances. In this paper, we demonstrate our expertise by utilizing unsupervised representation learning on accelerometer and hydrophone signals recorded during a fracture propagation experiment at the Sanford Underground Research Facility in South Dakota. Our UMAP-based representation executes a five-step process, including distance formulation, connection probability calculation, and low-dimensional projection using force-directed optimization. Our analysis shows that the short-time Fourier Transform of signals recorded by a single channel of the 3D accelerometer is the best feature extraction technique for representation learning. For the first time, we have successfully identified the distinct fracture planes corresponding to each micro-earthquake location using accelerometer and hydrophone data from an intermediate-scale hydraulic stimulation experiment. Our results from the EGS Collab project show the accuracy of this method in identifying fracture planes and hypocenter locations using signals from both accelerometers and hydrophones. Our findings demonstrate the superiority of UMAP as a powerful tool for understanding the underlying structure of seismic signals in hydraulic fracturing.
Wu, Bohong (Research Institute of Petroleum Exploration & Development, PetroChina) | Nie, Zhen (Research Institute of Petroleum Exploration & Development, PetroChina) | Li, Yong (Research Institute of Petroleum Exploration & Development, PetroChina) | Deng, Xili (Research Institute of Petroleum Exploration & Development, PetroChina) | Ma, Ruicheng (Research Institute of Petroleum Exploration & Development, PetroChina) | Xu, Jiacheng (Research Institute of Petroleum Exploration & Development, PetroChina)
Abstract Marginal reserves are an important play in future energy development. Based on the statistics of China National Petroleum Corporation (CNPC), the low permeability and unconventional reservoirs occupied 92% of newly found proven reserves in China. To overcome challenges such as poor reservoir conditions, weak natural energy, low displacement efficiency, and insufficient single well production, CNPC has conducted years of research and operation to cost-effectively develop China's marginal reserves. To develop the marginal fields economically, it is required to maximize single well production, recovery and reservoir sweep with minimum CAPEX and OPEX reasonably. The production enhancement is realized by 3 key technologies, namely, sweet spot identification, multi-layered 3D short spacing horizontal well pattern, and volumetric fracturing techniques. The cost reduction is achieved by the full life cycle practice of utilizing "large cluster, factory" well design and field operation, drilling prognosis optimization, integrated intelligent surface system, and unmanned operation. CNPC cost-effective development mode is practical and successful, marginal fields characterized with heterogeneous, multi-layered oil-bearing intervals with poor continuity are being economically developed in China. By comprehensive geological study, fit-for-purpose technologies application, and geoscience-to-engineering integration, the fracture control degree of horizontal wells increased from 60% to more than 90% based on micro-seismic events, stimulated reservoir volume (SRV) increased by 46.8%, average cumulative oil production per well is more than 100 times than original production in the field. Fast and early cash flow is realized by minimum production facilities. The average drilling cycle is shortened by 61%, the surface facility construction time is reduced by 65%, and the average single well investment is reduced by 42%.
Guan, Xu (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Zhu, Deyu (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Tang, Qingsong (PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Wang, Xiaojuan (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Wang, Haixia (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Zhang, Shaomin (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Deng, Qingyuan (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Yu, Peng (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Yu, Kai (Exploration and Development Research Institute of PetroChina Southwest Oil & Gasfield Company, Chengdu, China) | Huang, Xingning (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Xu, Hanbing (CNPC, International HK LTD Abu Dhabi, Abu Dhabi, UAE)
Abstract In recent years, tight sandstone gas as one of the important types of unconventional resources, has been rapid explored and developed. There are large-scale tight sandstone gas production in Sichuan Basin, Ordos Basin, Bohai Bay Basin, Songliao Basin and other basins, and it has become a key part in the area of increasing gas reserves and production in China. Due to the influence of the reservoir characteristics, tight gas reservoirs have low porosity and permeability, and the tight gas can only be effectively developed by improving the conductivity around the wellbore. Therefore, it is required to perform hydraulic fracturing after the completion of horizontal well drilling to improve the permeability of reservoir. It can be seen that hydraulic fracturing is the core technology for efficient development of tight gas resources. The implementation of hydraulic fracturing scheme directly determines the horizontal well production and EUR. This paper describes the workflow of 3D geomechanical modeling, technical application for Well YQ 3-3-H4 reservoir stimulation treatment, and carries out hydraulic fracture propagation simulation research based on 3D geomechanical model. This paper also compares the micro-seismic data with the simulation results, and the comparison results show that the propagation model is consistent with the micro-seismic monitoring data, which verifies the accuracy of the model. This paper clarifies the distribution law of hydraulic fractures in the three-dimensional space of horizontal wells in YQ 3 block, and the research results can be used to provide guidance and suggestions for the optimization of fracturing design of horizontal wells in tight gas of Sichuan Basin.
Ma, Jun (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Wang, Junping (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Fan, Qinghu (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Jiao, Shujiang (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Chen, Liang (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Guo, Changyong (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Hu, Zhangming (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Liu, Xiaodong (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Jiang, Xinmiao (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Wang, Yuan (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Huang, Xingning (Downhole service company of Xibu Drilling Engineering Company Limited, Karamay, China) | Xu, Hanbing (CNPC,International HK LTD Abu Dhabi, Abu Dhabi, UAE)
Abstract How to realize the efficient development of tight oil reservoir is a key and difficult problem for the unconventional resources of China. To realize the effective development of tight oil reservoir, it is necessary to the reservoir stimulation technology to improve the seepage capacity of low permeability reservoirs and increase the productivity of wells. Reservoir geomechanics is one of the main factors affecting hydraulic fracturing effect. Domestic and foreign experts have conducted a large number of studies on the characteristics of reservoir geomechanics. However, most of them studied the regional geomechanical characteristics based on logging data, lithology characteristics and three-dimensional seismic. Such static geomechanics studies can better reflect the in-situ stress characteristics of reservoirs before hydraulic fracutring but also have limitations and uncertainties in the understanding of regional geomechanical characteristics. Based on the one-dimensional geomechanical study, this paper uses structural characteristics and seismic attributes to study the three-dimensional mechanics spatial distribution characteristics of reservoirs. On this basis, this paper performs dynamic (4D) stress field simulation combined with real-time fracturing treatment and microseismic monitoring data. The research results can be used to guide the design of horizontal wells fracturing design and provide strong technical support for the production capacity construction. This paper studies the static and dynamic geomechanics of Baikou Quan Formation in Da 13 block, Junggar Basin and describes the research methods and processes and applies them to the design and optimization of reservoir stimulation schemes. The research results can help reduce operational costs and improve the efficiency of measures and serves as technical support for the efficient development of tight reservoirs in China.
Summary Most oil reservoirs are partially fractured, characterized by finite fracture networks (FFNs) in a sea of isolated fractures. It is necessary to determine size and shape of each FFN explicitly for reservoir simulation. FFN size is correlated with fracture connectivity, which is a function of fracture density, length, and angular scatter. Oil production from FFNs exhibits a long-term dual-porosity behavior. The initial fast rate (Phase I) represents depletion of matrix within FFN, and the subsequent gradual decline phase represents radial flow from the matrix outside the FFN perimeter. Thus, FFN size can be calculated from the cumulative oil production from Phase I, taking into account the pore volume, oil compressibility, and pressure decline. It is not always possible to identify the dual-porosity behavior by visual inspection. A mathematical model is needed to estimate FFN size. For this purpose, a set of three fundamental equations are derived for production rate, cumulative production, and pressure as a function of time. The model is a modified and simplified version of material balance equations with easy analytical solution. It is designed for fractured reservoirs with layer-bound fractures. Production is single-phase black oil under depletion drive. The analytical model was tested on four vertical wells. The unknown parameters such as FFN size, size of well drainage area, and fracture aperture are adjusted until an optimum fit to actual production data is obtained. FFN elliptical shape is estimated from average fracture strike and strike standard deviation. The results are validated by FFN size, fracture length, and aperture measurements from borehole images. The results are approximate but sufficient for preliminary mapping of FFNs with location and size and other critical attributes including fracture drainage area, matrix block size, fracture aperture, and permeability in partially fractured reservoirs.
Abstract In carbon capture and storage projects, and in unconventional plays, microseismic monitoring and optical fiber are critical components of the measure, monitor, and verify value chain. A velocity model is required to estimate source location (hypocenter), source parameters, and source mechanism of a detected microseismic event. Incorrect event locations are often the result of an inaccurate knowledge of the velocity model. We propose a new method to simultaneously invert for the hypocenter and the velocity model to provide a robust long-term microseismic monitoring workflow. Such problem has been studied in several areas of seismology over the last few decades. However, those studies focusing on large-scale earthquakes have remained of limited interest to reservoir-scale applications such as short-term and long-term microseismic monitoring and induced seismic monitoring. In such domains, the integration of sonic log-derived information into the joint inversion problem is critical as the scale is fundamentally different. Our algorithm respects the resolution of sonic measurement, while it calibrates the wavelength where microseismic data have sensitivity: the number of unknown parameters in the velocity model is decoupled from the number of layers included in the model. Therefore, we can solve for the velocity and event location inversion problem in a stable manner while respecting the resolution of the initial velocity model. In the present article, we introduce the science and technique behind the simultaneous inversion for the hypocenter and the velocity model and share case study applications based on a synthetic dataset and a real monitoring campaign.
Bachi, Hana (The University of Texas at Austin) | Wu, Jianfa (PetroChina Southwest Oil & Gas Field Company) | Liu, Chuxi (The University of Texas at Austin) | Yang, Xuefeng (PetroChina Southwest Oil & Gas Field Company) | Chang, Cheng (PetroChina Southwest Oil & Gas Field Company) | Yu, Wei (SimTech LLC) | Sepehrnoori, Kamy (The University of Texas at Austin)
Abstract Microseismic technology has proven its efficiency to monitor hydraulic fracturing effectiveness. The objective of this study is to develop a novel method to calibrate and generate the hydraulic fracture cluster-based model of a multi-stage horizontal shale well using the microseismic data. We use microcosmic numerical model known as Microseismic EDFM software feature (MSE-Frac) with the embedded discrete fracture model to simulate the hydraulic and natural fractures and the discrete fracture network. The MSE-Frac can handle the grouping of the clustered microcosmic events around the wellbore and generate a cluster-based model of the complex fractures network. Afterwards, we apply different factors on the hydraulic fractures, natural fractures, and the discrete fracture network to calibrate the fracture's geometry to match the historical data. This method allows us to determine the best parameters to be applied on this model to calibrate the hydraulic fracture geometry, and to find the fractures' characteristics for optimal production. Finally, we perform a production forecasting study for the next twenty years. Through this study, we develop a novel method to calibrate the complex hydraulic fracture geometry starting from the microseismic data. Four main parameters are investigated, namely, height and length cutoff, water saturation, compaction coefficient, and conductivity of the complex hydraulic fracture network. Multiple studies have been conducted to calibrate the geometry of the hydraulic fractures, but relatively less work is focused on utilizing the microseismic events even though they are largely available to most operators. Heretofore, there are no thorough studies on innovating a workflow to calibrate and position the fracture geometry starting from the microseismic events. Our models use more precise methodical approaches to simulate and calibrate the complex hydraulic fracture geometry based on microseismic events.
Abstract The combination of hydraulic fracturing and horizontal drilling unlocked a huge energy potential in the US. The unconventional plays have been developed by drilling several horizontal wells and hydraulically fracturing them to enhance the fluid flow. The implementation of these well can be done at the same time, known as Tank Development; however, due to the high capital expenditure and the increased risks associated with such an approach, in addition to the limited number of available drilling rigs. Operators try to hold the lease first by drilling one well, producing it, then extending the lease with additional wells. The challenge is that by producing from these wells, the stress and pore pressure state changes around the first wells (i.e., parent well). These changes directly affect the hydraulic fracture propagation from the offset wells (i.e., child wells). In this work, we build a numerical that represents a real case study. The model was calibrated using data from (a) Microseismic Depletion Delineation, (b) Microseismic events, (c) 10 years of production. Synthetic offset wells were implemented to run a sensitivity analysis on the well design (well spacing, cluster spacing, injection volume) and to understand how to design better wells that have been influenced by production from a primary well. The simulations were run for 10 years. The results show that wider well spacing results in better production, whereas lower cluster spacing had better production. This study allows operators to design better offset wells drilled next to a depleted parent well in the Bakken.
Han, Lihong (CNPC Tubular Goods Research Institute, State Key Laboratory for Performance and Structural Safety of Petroleum Tubular Goods and Equipment Materials, Chang'an University) | Yang, Shangyu (CNPC Tubular Goods Research Institute, State Key Laboratory for Performance and Structural Safety of Petroleum Tubular Goods and Equipment Materials) | Dai, Lei (Southwest University of Petroleum) | Cao, Jing (CNPC Tubular Goods Research Institute, State Key Laboratory for Performance and Structural Safety of Petroleum Tubular Goods and Equipment Materials) | Mou, Yisheng (CNPC Tubular Goods Research Institute, State Key Laboratory for Performance and Structural Safety of Petroleum Tubular Goods and Equipment Materials) | Wu, Xingru (University of Oklahoma)
Abstract When operators develop shale gas reservoirs in the southern Sichuan basin in China, they encountered numerous occurrences of casing deformations (CD) and even failures. The high frequency and severity of CD have led to significant financial loss. Since then, a considerable amount of research has been conducted with some field trials. Some research findings have been implemented in fields. The purpose of this paper is to present what we know and the trial results. We observed that casing deformation/failure were mainly in shearing failure and collapse modes. In the early stage of the development, most of the failure was due to shearing deformation caused by pre-existing geological features such as faults and weak interfaces. With the depletion of the reservoir and pressure decrease, casing collapses during the hydraulic fracture with extended length have become more and more popular in the later development stage. Laboratory tests on casing material and cementing material have shad lights on possible solutions. Increasing the casing wall thickness and cement thickness seems a viable solution for casing collapse, but the application of these recommendations yielded little effectiveness in mitigating casing deformation. Current operators redesigned a cementing material with high-strength beads which would collapse when stresses are above the designed threshold, which would "absorb" the formation displacement and reduce the severity of casing deformation caused by the aforementioned mechanisms. This paper summarizes the main research results from implementing numerical modeling and simulation. Based on that, we designed a special cementing with hollow high-strength particles in the cement slurry. In the later stage of fracturing, when the stress is above a threshold, the particles would burst and allow the casing to nudge slightly so that the deformation severity would be much less and more graduate. We implemented the new technology on 14 wells, and so far eight wells have been successfully completed without losses of horizontal segments. This new technology certainly brings hope for future study and provides field cases for future simulation work and laboratory studies for improvement.