Day 1 Tue, February 01, 2022最新文献

{"title":"Estimation of Far-Field Fiber Optics Distributed Acoustic Sensing DAS Response Using Spatio-Temporal Machine Learning Schemes and Improvement of Hydraulic Fracture Geometric Characterization","authors":"Kildare George Ramos Gurjao, E. Gildin, R. Gibson, M. Everett","doi":"10.2118/209119-ms","DOIUrl":"https://doi.org/10.2118/209119-ms","url":null,"abstract":"\u0000 Distributed Acoustic Sensing (DAS) is a fiber optics method that is revolutionizing the unconventional reservoir monitoring technology with substantial spatial coverage, high frequency data acquisition, and broad cable deployment options including hazardous/harsh environments compared to traditional geophysical methods such as point sensors (i.e., geophones). However, a single well equipped with fiber cannot acquire the far-field strain response since the sensitivity of this technique is restricted to a region near the monitor well. In this paper, we develop an Artificial Intelligence (AI) algorithm to estimate the magnitude of the far-field DAS response for any spatio-temporal input. Moreover, we identify a discontinuity in displacement results following fracture hit, which is interpreted as an effect of rock plastic deformation, and for the first time we demonstrate that it may be related to fracture width. Therefore, the output of our algorithm is used to estimate such geometric property along time in multiple locations.\u0000 We generate the tangent displacement component (uy) (parallel to monitor well) using an in-house code based on Displacement Discontinuity Method (DDM). Several monitor wells are incorporated in the simulation of physical scenarios characterized by single and multiple hydraulic fractures. For each specific scenario we train and test an Artificial Neural Network (ANN) with position and time as input variables, and axial displacement as output. The Machine Learning (ML) model is designed with 7 hidden layers, 100 the maximum number of neurons per layer and hyperbolic tangent as activation function. Finally, predicted uy is used to: (1) obtain Distributed Acoustic Sensing (DAS) data deriving it sequentially in space and time; and (2) estimate fracture width based on discontinuity magnitude.\u0000 Training stage is performed avoiding overfitting and minimizing ANN loss function. In the testing phase, error between true and predicted variables is negligible in the entire waterfall plot region, except at initial time steps where fracture treatment starts at operation well and magnitude of axial displacement collected at monitor well is very small on the order of 10-6 or even lower. In this case, we suspect that these tiny supervisor values may have minimal impact on the loss function, and consequently weights and biases of regression model are barely updated to consider the effect of such outputs. Regarding fracture width estimation, error reduces consistently along time at all locations reaching values near 0%.\u0000 To the best of our knowledge this is the first work that creates a ML algorithm able to estimate strain fields generated during hydraulic fracturing treatments merely based on position and time inputs. The model developed with synthetic data is an incentive for the deployment of multiple monitor wells in the field to enhance beyond the near wellbore region geometric characterization of created fracture systems, and possibly id","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129495215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Rigorous Coupled Flow-Geomechanics Semianalytical Approach for Analyzing Early Flowback Data from Multifractured Horizontal Wells with Complex Fracture Geometry","authors":"A. B. Lamidi, C. Clarkson","doi":"10.2118/209174-ms","DOIUrl":"https://doi.org/10.2118/209174-ms","url":null,"abstract":"\u0000 In this study, a rigorous coupled flow-geomechanics semianalytical approach is presented to analyze flowback data and forecast production performance in multifractured horizontal wells. Hydraulic fracture characterization using post-stimulation flowback data is of critical importance to the quantification of early-time well performance and for efficient development of unconventional reservoirs. However, conventional reservoir (flow) simulators can be challenging to setup for flowback analysis. Further, flow simulators usually approximate stress-dependence of fracture and reservoir parameters, the former of which is particularly important to capture for both the flowback and forward modeling problem, using porosity and transmissibility multipliers. However, in order to apply this approach, transmissibility multipliers must be estimated from laboratory experiments, or used as a history-match parameter, possibly resulting in large errors in performance predictions. The goal of this study is to provide a rigorous, coupled semianalytical workflow for hydraulic fracture characterization from flowback data, that utilizes a 3D coupled flow-geomechanics semi-analytical model as its basis.\u0000 A 3D semi-analytical coupled flow-geomechanical model is developed to capture the complexities of stress-dependence in order to forecast production performance from multifractured horizontal wells. The model can also be used to derive hydraulic fracture properties from early post-stimulation flowback data. An enhanced fracture region (EFR) conceptual model is applied for approximating complex fracture geometries. The fully-analytical fluid flow and semi-analytical geomechanical models are coupled for both the fracture and reservoir regions. The proposed approach requires simultaneous solutions of the fluid flow model (reservoir simulation) and geomechanics model, the latter capturing the stress and deformation behavior of the fracture and reservoir. Coupling between fluid flow and geomechanics is achieved by updating the pressure and stress-dependent properties through a porosity function (coupling parameter) in the flow model for each region (hydraulic fracture and reservoir) at each iteration step.\u0000 The coupled flow-geomechanics EFR model is validated with fully-numerical simulation. Fracture properties are estimated by using the proposed inverse model for analyzing flowback (water) data. The new flowback analysis approach is applied to synthetic field data and the results compared with the inputs of the synthetic model.\u0000 With this model, combined with the semi-analytical coupled flow-geomechanics workflow, a more confident estimate of hydraulic fracture properties is obtained.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128671130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geomechanical Applications in Deepwater Fracpacks and Associated Productivity Impact","authors":"Karthik Mahadev, Jianguo Zhang","doi":"10.2118/209176-ms","DOIUrl":"https://doi.org/10.2118/209176-ms","url":null,"abstract":"\u0000 Deepwater fracpacks continue to evolve in the Miocene and Paleogene trends in Gulf of Mexico and deliver best in class skins and reliability in these high-rate high margin reservoirs. As operators move towards maximizing production in existing fields that have been produced over the past several decades, depletion has concurrently evolved as the most frequent issue that challenges drilling, cementing, perforating, and fracturing operations. The overall impact of higher overbalance operations in these depleted intervals has placed Geomechanical impacts on completions and well productivity at the forefront. The paper will examine recent advances in Geomechanical applications in high permeability formations, specifically in a fracturing context.\u0000 This paper will expand upon a simple and innovative method for the determination of maximum horizontal stresses with calibrated minifrac data that will have an impact on fracturing and proppant placement. Use of pore pressure ranges to correlate fracture initiation and breakdown pressures will also be demonstrated as a valuable aid to design surface equipment pressure limits to enable fracturing.\u0000 Applying depletion related Geomechanical concepts to fracpacks has resulted in understanding of high treating pressures, bring successful investigations on trouble fracturing treatments to closure, and capture lessons to avoid problems on future wells. A robust workflow process has also been developed to anticipate these potential challenges and appropriate mitigations such as higher ratings for surface equipment, differential packer ratings and completion fluid weight to gain higher margins and were incorporated to enable fracture placement as designed. This will be discussed in the context of a few actual case histories from the Gulf of Mexico. The effect of depletion and well bore trajectory on fracture placement will also be discussed.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124974813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization and Design of Next-Generation Geothermal Systems Created by Multistage Hydraulic Fracturing","authors":"M. McClure, Charles A. Kang, G. Fowler","doi":"10.2118/209186-ms","DOIUrl":"https://doi.org/10.2118/209186-ms","url":null,"abstract":"\u0000 Multistage hydraulic stimulation has the potential to greatly expand the production of geothermal in the United States and worldwide. Zonal isolation and limited-entry completion overcome the problem of flow localization and generate hundreds or thousands of conductive fractures throughout a large volume of rock. In contrast, conventional geothermal stimulation designs are bullheaded as a single stage into a vertical or deviated wellbore, resulting in a small number of dominant flow-pathways. In this study, we perform a modeling study to investigate key physical processes and design considerations for a geothermal system created from multistage hydraulic stimulation. We use a simulator that fully integrates a wellbore simulator, a hydraulic fracturing simulator, and a thermal/compositional reservoir simulator. Thermoelastic and poroelastic stress changes are included, which enables the model the simulate mechanical opening (separation of fracture walls) due to cooling during long-term fluid circulation between wells. The simulator can handle the full life-cycle in a single continuous simulation – multistage fracturing (including crack propagation, proppant, limited-entry, etc.) and long-term circulation. We start by reviewing historic background on the application of hydraulic stimulation to improve geothermal energy production. Next, we discuss key uncertainties regarding stimulation mechanism and fracture geometry. Drawing on this background information, we set up simulations of multistage hydraulic fracturing and long-term fluid circulation through an injector/producer pair. The simulations demonstrate how multistage fracturing enables large flow rates and relatively efficient sweep of heat through large volumes of rock. However, the simulations demonstrate how mechanical opening of fractures due to thermal contraction exacerbates thermal short-circuiting. Produced temperature drops rapidly once mechanical opening reaches the production well. Parameters such as well spacing, fracture spacing, and flow rate can be designed to mitigate thermal breakthrough and maximize discounted return on investment. We integrate the simulator with an optimization algorithm to solve a hypothetical engineering design problem to maximize net present value by optimizing well spacing, fracture spacing, and flow rate. The optimization shows how a balance can be struck between rate acceleration and mitigation of thermal breakthrough.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133973874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Importance of Preexisting Fractures to Completion and Production Efficiencies in the Marcellus Shale Energy and Environmental Lab MSEEL","authors":"T. Carr, E. Fathi, Rob Bohn, M. F. Adenan, Liwei Li, Brian J. Panetta, B. Carney, N. Mitchell","doi":"10.2118/209147-ms","DOIUrl":"https://doi.org/10.2118/209147-ms","url":null,"abstract":"\u0000 The Marcellus Shale Energy and Environmental Lab (MSEEL) provides a publicly available dataset and a hypothesis-driven field test of the significance of preexisting natural fractures at multiple scales on the effectiveness of the stimulation of an unconventional reservoir. Sonic and microresistivity imaging show the presence of numerous preexisting cemented fracture swarms, which are evaluated in terms of their influence on the fracture stimulation. Natural fracture intensity in the Boggess 5H and MIP-3H were interpreted based on wireline and logging while drilling (LWD) image logs showing that 1000's of calcite and bitumen cemented, but relatively weak, fractures are present along the laterals as swarms that are at an angle to the present-day stress regime. Fractures with complex bitumen and calcite filling were recognized in cores from pilot wells at the micro and macroscales (micron to millimeter). The importance of pre-existing fractures on geometric stimulations was evaluated and compared to cluster locations that avoided intense preexisting fractures using fiber-optic distributed acoustic and distributed temperature sensing (DAS/DTS) data and supported by production and simulation. Fiber-optic DTS and DAS measurements were coupled with wireline and LWD image logs from the lateral to recognize preexisting and cemented fractures. This data is supplemented with core analysis including (CT and thin sections) from vertical pilot wells shows that clusters in parts of a stage dominated by preexisting fractures have significantly more hydraulic fracture activity to the point that other clusters appear largely inactive. In addition, processed fiber-optic data indicates that preexisting fractures can form near-well bore leak-off pathways to previous stimulated stages. Both can lead to stimulation and subsequent production inefficiencies. Two wells (Boggess 1H and 3H) that attempted to avoid preexisting fractures showed a significant increase in fracture stimulated volume based on decline curve analysis and microseismic. Production history and simulated future production support the conclusion that avoiding preexisting fractures in the Marcellus Shale can increase estimate ultimate production. We present conclusions about stage and cluster spacing and the significance of preexisting natural fractures on stage isolation and fracture efficiency. The publically available data and workflow allow others to use, verify, and evaluate our findings using the same initial data.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125063587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Practical Design Considerations for Perforation and Stimulation Strategy Based on Two Permanent Fiber Optics Tests in the Williston Basin","authors":"L. Ribeiro, Wesley Zurovec","doi":"10.2118/209183-ms","DOIUrl":"https://doi.org/10.2118/209183-ms","url":null,"abstract":"\u0000 This paper introduces the results and interpretation of two permanent fiber optic (FO) installations deployed on two plug-and-perf wells in the Williston Basin. The paper covers a wide range of completion parameters that were tested and later implemented at scale as part of the field development strategy.\u0000 Recent publications from multiple operators have demonstrated the success of aggressive limited entry strategies to reverse the decade-long trend of reducing stage length (to accommodate higher cluster counts and stimulate more entry points) in favor of extended stage lengths with higher cluster counts per stage. The paper provides additional field data supporting this trend with an emphasize on key design parameters that enable an increase in stimulated surface area while decreasing costs. We also share practical guidelines and field recommendations to mitigate risks during FO deployment.\u0000 Finally, we demonstrate the value of the integrated application of field trials, fracture diagnostics, and well performance analysis to improve the stimulation design and capture additional value. The FO results enabled us to increase clusters per stage without diminishing cluster efficiency and allowed us to understand the dynamic of perforation screen-out and how variations in proppant schedules can impact cluster efficiency.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128692905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing XLE For Cost Savings in the DJ Basin: A Fiber Optic Case Study","authors":"Jessica Barhaug, Jacqueline Bussey, Ben Schaeffer, J. Shemeta, M. Lawrence, J. Tran, P. Stark","doi":"10.2118/209155-ms","DOIUrl":"https://doi.org/10.2118/209155-ms","url":null,"abstract":"\u0000 Historically, Great Western Petroleum has been an operator focused on efficiency without much focus on altering completion designs. Based on the successes of Extreme Limited Entry (XLE) in other basins, a science project was constructed to test different XLE in the first zipper group of a two-zipper group pad. The goal was to find a design that would yield the same production, but with less cost. Increasing stage length provides a significant cost saving and with XLE, production should be maintained. Based on the results from zipper one, the best design could then be implemented on the same pad in the second zipper group. This allows for a direct comparison of hydraulic fracturing designs, minimizing geologic impact.\u0000 This study was comprised of a number of different datasets with the primary focus being on Distributed Acoustic Sensing (DAS) using wellbore fiber optic cable. DAS is a rapidly evolving technology with numerous advances in both function and cost over the last few years, especially in fiber optic cable deployment. An opportunity was seen to not just gather data, but to test the data quality of the latest deployment methods, specifically a pump-down dissolvable, single-use fiber optic cable. This is a cost effective and minimal footprint option for data collection. This project included three acquisition methods for the DAS: 1) a permanent fiber optic line cemented on the outside of the casing, 2) a wireline retrievable fiber optic line, and 3) a pump-down dissolvable single-use fiber, all deployed in three unique wellbores. The permanent fiber optic well was used to compare the uniformity index of different completion designs. The designs were altered based on the results from the previous stage until an optimal design was reached. This DAS acquisition also provided offset strain and microseismic in the first and second zipper groups. The wireline retrievable fiber optic cable and single-use fiber optic cable deployments provided offset strain and microseismic for the wells in the first zipper group. High level observations resulting from this project include: The data quality associated with the dissolvable single-use fiber looked comparable in data quality to the other fiber optic deployment methods.The Uniformity Index was high for most designs, even with stages as long as 450 ft and cluster spacing as tight as 7 ft.350’ stages with 14 clusters at 1 spf was chosen for the second zipper group wells This provided significant cost savings, along with high stage uniformityResults from the offset strain and microseismic analysis from tighter and more clusters per stage showed less interference than what was seen with our legacy design stagesRTA shows that compared to a pad with similar well spacing, the production is better with the new hydraulic fracture design\u0000 Having a case study with various fiber optic deployments is rare. At the time of this deployment, this was the first pump down dissolvable single-use fiber optic line in Nor","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127159426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theory and Practice of a Flexible Fiber Optic Cable in a Horizontal Well Used for Cross-Well and Microseismic Hydraulic Fracture Monitoring","authors":"M. Leblanc, K. Suh, S. Machovoe, Dane Byrd, Mikko Jaaskelainen, H. Bland, J. Stokes, T. Henao, Neha Sahdev","doi":"10.2118/209121-ms","DOIUrl":"https://doi.org/10.2118/209121-ms","url":null,"abstract":"\u0000 A flexible optical fiber cable, either as a wireline or a disposable fiber deployed using a pumped fiber payout shuttle, in a horizontal well, can be used be measure distributed near-static or dynamic strain. These measurements can be used to monitor the hydraulic fracturing treatment of nearby wells. It is the objective of this paper to present a theoretical framework for the understanding of the cable behavior and to compare it to field measurements.\u0000 The theory predicts the conditions under which slippage occurs between the optical fiber cable and the wellbore if coupling is provided by Coulomb friction. For near-static strain, as used in crosswell strain monitoring, the theory explains the broadening of the strain zone detected with a wireline cable. However, the theory underestimates the coupling provided by a grease-covered disposable fiber where a level of adhesion between the fiber and the wellbore provides better coupling than possible by Coulomb friction alone. Understanding the fundamental theory explains measured data and enables confident data interpretation regardless of sensing cable configuration.\u0000 For the dynamic strain, the theory confirms the generally good response observed using the flexible cables for microseismic monitoring due to the low amplitude of the dynamic strains involved. The low amplitude of the strains means that the strain gradients and inertial forces are also small, such that Coulomb friction is sufficient to provide the needed coupling.\u0000 An interesting result of the theory is the existence of a resonance condition allowing for large amplitudes to be detected faithfully even if only Coulomb friction is present. This resonance does not depend on signal frequency but on the match between the intrinsic travel speed of a disturbance on the cable and the apparent phase velocity of the seismic signal in the well direction.\u0000 Most importantly, the theory enables i) a comparison of different cable types for the near-static and dynamic strain applications, and ii) better data interpretation and associated decisions.\u0000 Field examples are provided to show both when the theory is applicable and where the obtained coupling exceeds what is predicted by the theory. The novel aspect of the paper is the first presentation of a theoretical background for the understanding of the performance of flexible cables inside horizontal wells used as static or dynamic strain sensors for the monitoring of hydraulic fracturing jobs.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115605369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Investigation of Low-Frequency Distributed Acoustic Strain-Rate Responses to Propagating Fractures","authors":"S. Leggett, T. Reid, D. Zhu, A. Hill","doi":"10.2118/209135-ms","DOIUrl":"https://doi.org/10.2118/209135-ms","url":null,"abstract":"\u0000 Low-frequency distributed acoustic strain-rate sensors (LF-DAS) experience strain changes due to far-field fracture propagation. To better understand the LF-DAS response to fracture propagation, we performed laboratory-scale hydraulic fracture experiments with embedded optical strain sensors. The objectives of this research are to generate hydraulic fractures of known geometry, measure the strain response along the embedded fiber optic cable comparable to LF-DAS measurements, and use the results to inform interpretation of field-derived LF-DAS data.\u0000 The experiments were conducted in unconfined transparent cubic blocks with a dimension of 8-inches on each side. The block was made of transparent epoxy in order to visualize the fracture propagation. Fiber optic sensing cables were embedded in the block with different distances to the source of injection. We injected dyed water through an injection tubing to generate a transverse, radial fracture along an initial flaw. An optical interrogator recorded the response of offset fiber Bragg grating strain sensors normal to the plane of the fracture. The strain data was visualized on a waterfall plot, akin to visualizations of field-derived LF-DAS data. Dimensional analysis was used to scale the lab results to field conditions. We compared the evolution of the strain response at the fiber optic cable, injection pressure, and rate with known fracture geometry. The measured strains were compared to Sneddon's (1946) linear elastic solution for a penny-shaped crack and found to follow this behavior.\u0000 The generated radial fractures in transparent media can be modeled with Sneddon's linear elastic radial fracture model and a mode I critical stress intensity factor. The LF-DAS characteristic response of a narrowing region of extension surrounded by compression was exhibited as a fracture approached and intersected the fiber optic cable. The experimentally derived strain and strain-rate waterfall plots with known fracture geometry, injection rate and pressure response provide insight in understanding LF-DAS responses in the field. Furthermore, we developed a method to estimate fracture geometry evolution from the fiber optic strain data and validated the method against the experimental data.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126186545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Complex Fracture Networks on Well Productivity: A Case Study of the Hydraulic Fracturing Test Site #2","authors":"M. Cao, Shuang Zheng, Brendan Elliott, M. Sharma","doi":"10.2118/209131-ms","DOIUrl":"https://doi.org/10.2118/209131-ms","url":null,"abstract":"\u0000 For simplicity, planar fractures are usually used for simulating well performance. This is clearly an oversimplification for naturally fractured formations. Core data from both HFTS 1 and 2 show that a much more complex fracture network is created. In this work, a novel three-dimensional fracturing-reservoir simulator is applied to the Hydraulic Fracturing Test Site (HFTS2) data to provide a thorough assessment of the impact of the fracture network on well performance. A methodology is also presented to effectively represent realistic complex fracture networks generated by hydraulic fracturing when simulating well productivity.\u0000 Data that characterizes the natural fractures at HFTS 2 are used to create a realistic representation of the reservoir. A fracturing simulator which fully couples fluid flow, fracture mechanics and a black oil reservoir simulator is used to first create the fracture network and then simulate flowback and production. The complex fracture networks, generated by fracture propagation is compared with the core data collected at the site. The production flowback results are also compared with the field and are found to agree well with actual production data.\u0000 We demonstrate a workflow to create a realistic natural fracture network based on core data. A comparison of our simulation results with core data shows good agreement with the characteristics of the NF network based on the post-frac core analysis. The characteristics of this fracture network control the well productivity. While it is possible to use planar fractures to history match production, the results provide unrealistic fracture dimensions and reservoir drainage volumes. This directly impacts design and operational decisions related to well spacing and fracture sizing demonstrating the importance of incorporating realistic complex fracture networks into reservoir simulators for production evaluation and forecasting as well as fracture design and selecting well spacing.\u0000 In this paper the rich dataset provided by HFTS-2 is used to demonstrate a methodology to generate a realistic natural fracture network and to create hydraulic fractures that create a fracture network that can be used to simulate well productivity and reservoir drainage. The results show that it is possible to simulate the creation of complex fracture networks that provide much more realistic estimates of well productivity and reservoir drainage area. This is essential for fracture sizing and estimating the optimum well spacing.","PeriodicalId":262088,"journal":{"name":"Day 1 Tue, February 01, 2022","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126777101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}