Day 1 Mon, September 30, 2019最新文献

{"title":"In-Situ Stresses in Colorado Group, AB, Calculated from Open-Hole Mini-Fracs and FMI Logs","authors":"O CostinSimona, R. Smith, Yanguang Yuan, D. Andjelković, Gabriel Garcia Rosas","doi":"10.2118/196037-ms","DOIUrl":"https://doi.org/10.2118/196037-ms","url":null,"abstract":"\u0000 Open-hole mini-frac tests are seldom performed in the Athabasca and Cold Lake oil sands due to the complexity of operations. In this paper we present the results of open-hole injections tests performed in Cold Lake, Alberta (AB), Canada. The objective of the injection tests was to assess the in-situ stress condition in the Cretaceous Colorado Group. The injection tests results combined with the run of formation image logs (FMI) before and after the injection have enabled not only the determination of the in-situ minimum stress in the rock, but also the full 3-D stress tensor, along with the orientation and inclination of the hydraulic fracture.\u0000 The tests were performed in IOL 102/08-02-066-03W4 (N10 Passive Seimic Well, ‘PSW’). The injection tests have revealed that the vertical stress in the area is the in-situ minimum stress, consistent with previous measurements. The hydraulically-induced fracture has sub-horizontal to moderate dip angle, mostly owing to the pre-existing fabric of the rock, and peaks in the general NE-SW direction. Numerical modeling of the in-situ stresses has shown that the values of the vertical and the minimum horizontal stresses are close, with the vertical stress consistently being smaller than the minimum horizontal stress in all tested zones.","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125685267","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":"Non Aqueous Foam for Improving Hydrocarbon Miscible Flooding in Water Sensitive Tight Oil Formations","authors":"Chao-yu Sie, Q. Nguyen","doi":"10.2118/196162-ms","DOIUrl":"https://doi.org/10.2118/196162-ms","url":null,"abstract":"\u0000 Enhanced oil recovery from tight carbonate formations has been challenging due to its high reservoir heterogeneity, unfavorable wettability to water, and low reservoir permeability which can restrict the application of traditional water-based EOR methods with mobility control (e.g. polymer). With the increasing availability of wet gas due to the rise of shale production over the last decade, we introduce a novel foam EOR utilizing the raw mixture of constituents of Natural Gas Liquids Mixture (NGLM) composed principally of ethane, propane, butane, and natural gasolines. This process involves the injection of NGLM with non-condensable gas (i.e. nitrogen) and non-aqueous foam stabilizing additive (such as surfactant) to simultaneously maximize the displacement efficiency based on its miscible nature and the sweep efficiency due to the mobility control as provided by the NGLM-based foam. The objectives of this study are to (i) investigate the feasibility of this non-aqueous-foam-enhanced miscible hydrocarbon flooding in sub-10-mD carbonate cores, and (ii) evaluate the effect of the non-aqueous foam on miscible displacement.\u0000 The proof-of-concept study of non-aqueous foam assisted miscible displacement were conducted by performing a series of core floods in heterogeneous carbonate cores with sub-10-mD permeability. The effect of foam on oil recovery performance was evaluated based on the ultimate recovery factor and oil recovery rate. The effect of injection strategy (continuous drive injection and alternating injection) on non-aqueous foam propagation and overall recovery were evaluated and compared. The propagation of foam and the mobilization of the unswept oil were monitored based on the measured pressure drops of the core.\u0000 It was found that non-aqueous foam-assisted miscible flooding can achieve promising ultimate recovery factor while significantly reducing the amount of injected NGLM. For the reference case (continuous NGLM injection), an ultimate recovery factor of 87.6% was achieved after 2.06 PV of NGLM injection. High ultimate recovery factor may be attributed to (i) the miscibility between NGLM and oil, and (ii) gravity stabilization (top-down injection). For continuous nitrogen drive (0.33 PV of NGLM slug followed by a nitrogen drive), a low ultimate recovery factor of 47.4% was observed due to the acceleration of the injectant breakthrough as caused by the extremely unfavorable mobility ratio between nitrogen and crude oil. With the non-aqueous foaming agent, the ultimate recovery factor for the continuous nitrogen drive was increased by 15.7%. Comparison between the overall and sectional pressure drops in these two cases indicates that the in-situ generation of non-aqueous foam significantly delayed the injectant breakthrough and recovered the unswept oil in the sections closer to the producer. For alternating injection, the ultimate recovery factor of the case with the foaming agent (87.5%) is 17.8% higher than that without the foa","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"301 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127816620","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":"Quality Control of LWD Resistivity Data Inversion Results","authors":"M. Sviridov, Yuriy Antonov, S. Martakov, N. Tropin, H. Andersson","doi":"10.2118/195817-ms","DOIUrl":"https://doi.org/10.2118/195817-ms","url":null,"abstract":"\u0000 Drilling operators very often perform reservoir navigation and mapping using extra-deep resistivity tools. Tool responses depend on formation properties tens of meters away from the wellbore and require sophisticated processing by inversion to provide operators with a multilayer resistivity model. The accuracy and reliability of inversion results are very important and need thorough assessment. We present two new methods of inversion quality control, validate their applicability, and provide a comparative analysis with existing methods on several synthetic and field cases.\u0000 Deterministic and statistical methods of estimation of resistivity, tool detection, and resolution capabilities are applied to evaluate the quality of inversion results. We discuss tool ability to detect single boundary, depth-of-detection (DOD) and depth-of-reliable-detection (DRD) concepts based on covariance matrix analysis, and introduce a new method of DOD estimation based on resistivity model perturbations, with posterior tool response monitoring. We propose a new statistical resolution analysis method related to response-surface technique and compare its results with other approaches. The applicability of the methods considered is validated by guided inversion for typical job stages (pre-well, real-time, post-well) and applications (landing, reservoir navigation, mapping).\u0000 Inversion results for extra-deep logging-while-drilling (LWD) resistivity tools are usually shown as a multi-layer resistivity distribution map or picture, without a clear indication of the uncertainty of the structures presented on the picture. The uncertainty of inversion results depend not only on tool specifications (i.e., frequency range, electronic noise level and antennae spacings), but on the complexity of surrounding formations as well. The new method for DOD estimation deals with model complexity and gives several estimates based on different subsets of measurements. Common approaches to inversion result quality control only provide partial reliability indicators, usually around the final inverted model. The suggested resolution analysis method generates a statistic from models assessed during inversion execution, analyses it, and eventually provides the resolution accuracy of formation parameters. The method enables identification and quantification of disconnected uncertainty regions, when they exist, thus ensuring an exhaustive analysis of the parameter space. Based on synthetic and field cases considered, we conclude that understanding of uncertainties associated with reservoir navigation requires the application of several data analysis techniques. Complementary use of data inversion, DOD estimation and resolution analysis yield a comprehensive evaluation of the environment and show the realistic capabilities of the tool. The developed methods enabled the implementation of scenario-oriented workflows that deliver not only the final resistivity model but also its reliability indicator","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"462 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131524724","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":"Understanding the Mechanism of Breaking Polyacrylamide Friction Reducers","authors":"Linping Ke, Hong Sun, Melissa C. Weston, Jason Wallbaum, H. Fitzpatrick","doi":"10.2118/196107-ms","DOIUrl":"https://doi.org/10.2118/196107-ms","url":null,"abstract":"\u0000 Partially hydrolyzed polyacrylamide (PHPAM)-based friction reducers (FRs) are widely used in stimulation treatments because of their favorable economics and operational simplicity. The use of these materials, particularly at higher concentrations, has increased substantially in the past two years. FR materials have extremely high molecular weight; consequently, breakers are recommended to reduce polymer size and to mitigate potential damage to fracture conductivity, microfractures or secondary fractures, and the formation. A better understanding of the breaking mechanism of FRs and the performance of various types of common oilfield breakers will help to improve job designs and to maximize the benefit of slickwater fracturing.\u0000 Radical-generating breakers (RGBs), persulfate- and non-sulfate-containing peroxygen breakers, and non-radical-generating breaker (NRGB), bromate breaker, were studied in the breaking of a PHPAM-based FR. Static break tests were performed at 150, 200, and 290°F with a setpoint of 8 gal/Mgal FR using two RGBs, two NRGBs, and their corresponding encapsulated versions. The efficiency of the breakers, at various concentrations and temperatures, was evaluated by measuring broken fluid viscosities, determining molecular weight, and performing regained permeability testing. The kinetics of the breaking reaction was determined by studying the molecular weight profile by gel permeation chromatography-multiangle laser light scattering (GPC-MALLS) of a fluid over time.\u0000 This study reveals that RGBs break PHPAM rapidly and more effectively than NRGBs. At 290°F, it is shown that NRGBs must be used at eight times the concentration of RGBs to achieve the same break quality and time. Encapsulated RGBs perform more slowly than non-encapsulated RGBs and may provide an effective method of retaining viscosity below 200°F, which may aid in proppant transport and placement. Encapsulated NRGBs are extremely sluggish in reducing fluid viscosity and require very high loadings to achieve results comparable to RGBs.\u0000 Fluid formulations designed with the correct RGBs, at an optimal concentration, render a steady viscosity decrease and a sufficiently low final viscosity, near that of water, to aid in cleanup and flowback. FR broken with RGBs offer high regained permeability, indicating effective and complete breaking of polymer chains. These results are significant for well productivity and confirm that the degradation of FRs proceeds in a radical pathway, rather than in a pure oxidation manner. Strong oxidants, if incapable of generating radicals, are not good candidate breakers for FRs, regardless of their oxidative potentials. Random chain-scission seems to be the most efficient means of breaking PHPAM FRs.\u0000 This study clearly demonstrates that RGBs degrade polyacrylamide FRs effectively, whereas NRGBs are not recommended under the same treatment conditions, even at significantly higher concentrations. An Ubbelohde capillary viscometer has proven","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134349774","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":"Simple, Systematic Reserves Estimation for Unconventional Wells","authors":"Cheryl Cartier, P. Miller, Peter Wagner","doi":"10.2118/195851-ms","DOIUrl":"https://doi.org/10.2118/195851-ms","url":null,"abstract":"\u0000 Booking reserves for unconventional, multi-frac wells is a critical business process, but to be done effectively, often requires significant time investment and multiple interpretation techniques. Although reserves can be estimated quickly with decline curve analysis (DCA) alone, the subjectivity in DCA makes it challenging for evaluators to estimate reserves with appropriate levels of uncertainty and maintain consistency between evaluators. The objective of this paper is to present a fast, systematic, yet rigorous methodology for estimating 1P, 2P and 3P estimated ultimate recoveries (EURs) for new wells. This methodology utilizes regression to correlate easy to obtain, early life indicators of well performance to 2P EURs, which have been estimated from more detailed interpretations. Multiple methodologies are presented for estimating 1P and 3P EURs.","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130277340","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":"Multi-Frequency Modeling of Dielectric Measurements in the Presence of Complex Rock Fabric and Composition","authors":"Artur Posenato Garcia, Z. Heidari","doi":"10.2118/195815-ms","DOIUrl":"https://doi.org/10.2118/195815-ms","url":null,"abstract":"\u0000 The low-frequency dielectric response of sedimentary rocks is dominated by rock fabric, volumetric concentrations of fluids and minerals, and interfacial properties. The rock physics models for interpretation of multi-frequency complex permittivity measurements generally rely on simplified geometries for which analytical solutions are obtainable. Consequently, interpretation of permittivity measurements can be challenging in reservoirs with complex pore structure, mineralogy, and mixed-wet conditions. The objectives of this paper include the development of a rigorous numerical simulation framework to enhance the interpretation of multi-frequency, complex dielectric permittivity measurements and also to quantify the influence of polarization of the electric double layer, lithology, fluid properties, and pore-network geometry on dielectric permittivity measurements.\u0000 We develop a simulator to calculate permittivity dispersion of sedimentary rocks by applying a combination of finite-difference and finite-volume methods to solve the non-linear Poisson and Nernst- Planck equations in the time domain. We perform a sensitivity analysis of dielectric permittivity to the dominant mineral (e.g., quartz, calcite), pore geometry, and fluid properties (e.g., salt concentration). The main contribution of this paper consists of introducing a simulator that provides the complete and accurate description of electric field, ionic distribution, and effective dielectric permittivity in porous media for enhanced petrophysical interpretation of electromagnetic measurements. Results suggest that incorporating the introduced simulation into a workflow for broadband interpretation of dielectric measurements can improve petrophysical evaluation in formations with complex lithology, rock fabric, and in mixed-wet rocks. This unique approach provides a more rigorous characterization of the dielectric permittivity of rocks than previously documented analytical and numerical models.","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130778236","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":"Mexico Pilot Project to Classify Oil and Gas Projects Using United Nations Framework Classification UNFC","authors":"S. Purewal, Fidel Juárez Toquero, Eduardo Simón Burgos, Eduardo J. Meneses-Scherrer, Elaine A. Arellano Sánchez","doi":"10.2118/196566-ms","DOIUrl":"https://doi.org/10.2118/196566-ms","url":null,"abstract":"\u0000 A Pilot project was initiated to classify Oil and Gas projects in 19 Blocks in Mexico using the United Nations Framework Classification (UNFC) which has a unique 3-dimensional evaluation structure with three axes: Economics, Environment and Social viability (E axis), Project Feasibility (F axis) and Geological Knowledge (G axis). The main focus was to capture the environmental and social impact on project classification and resources categorization.\u0000 The Pilot project was coordinated by the National Hydrocarbons Commission (CNH) with integrated collaboration from the Energy Ministry (SENER), the Agency for Safety, Energy and Environment (ASEA), and the Petroleum Work Group of UNECE. SPE classification system (i.e. PRMS) has been mapped to UNFC. While PRMS covers oil and gas projects only, UNFC covers all resources e.g. oil and gas, minerals, renewables, nuclear, etc.\u0000 The E axis uniquely differentiates UNFC from PRMS by its granular capture of social and environmental issues. A systematic approach was adopted with focus on E and F axes for which a matrix and a decision tree (‘flow chart’) were created for an efficient classification of the hydrocarbon volumes. For the G axis, the volume ranges provided by the project operators were considered to be valid. In the selected 19 blocks, there were 75 projects identified. These were located offshore, onshore and included conventional and unconventional projects with varying degrees of environmental and social issues.\u0000 This is the first known exercise using UNFC for integrating social and environmental issues into oil and gas projects for hydrocarbon volumes classification and categorization anywhere globally. The outcome shows the differences between the PRMS and UNFC due to social and environmental conditions. Using UNFC for classification and categorization of all energy sources of a country, a potential tool can be created for making energy policy decisions. This may also assist in meeting Sustainable Development Goals- 2030 adopted by most countries including the UN and The World Bank.\u0000 Classification using UNFC assists in identifying the key social and environmental drivers which may be impediments to moving the oil and gas volumes categorizations higher up the value chain. Added granularity in the classifications incorporating environmental and social considerations will assist project financial investment decision making through comparative assessment of objectives and priorities of national, regional and local stakeholders. To the authors’ knowledge, this is a unique Pilot project with significant value-add outcomes which can be replicated in other countries.","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124889227","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":"CT Coreflood Study of Transient Foam Flow with Oil","authors":"Jinyu Tang, S. Vincent-Bonnieu, W. Rossen","doi":"10.2118/196202-ms","DOIUrl":"https://doi.org/10.2118/196202-ms","url":null,"abstract":"\u0000 We present a CT coreflood study of foam flow with two representative oils: hexadecane C16 (benign to foam) and a mixture of 80 wt% C16 and 20 wt% oleic acid (OA) (very harmful to foam). The purpose is to understand the transient dynamics of foam, both generated in-situ and pre-generated, as a function of oil saturation and type. Foam dynamics with oil (generation and propagation) are quantified through sectional pressure-drop measurements. Dual-energy CT imaging monitors phase saturation distributions during the corefloods. With C16, injection with and without pre-generation of foam exhibits similar transient behavior: strong foam moves quickly from upstream to downstream and creates an oil bank. In contrast, with 20 wt% OA, pre-generation of foam gives very different results from co-injection, suggesting that harmful oils affect foam generation and propagation differently. Without pre-generation, initial strong-foam generation is very difficult even at residual oil saturation about 0.1; the generation finally starts from the outlet (a likely result of the capillary-end effect). This strong-foam state propagates backwards against flow and very slowly. The cause of backward propagation is unclear yet. However, pre-generated foam shows two stages of propagation, both from the inlet to outlet. First, weak foam displaces most of the oil, followed by a propagation of stronger foam at lower oil saturation. Implicit-texture foam models for enhanced oil recovery cannot distinguish the different results between the two types of foam injection with very harmful oils. This is because these models do not distinguish between pre-generation and co-injection of gas and surfactant solution.","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125155144","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":"Lessons Learned from Effective Well Integrity Management in Offshore Field","authors":"A. Al-Dhafeeri, Shebl Fouad Abo Zkery, Saad Ahmed Al Sdeiri","doi":"10.2118/195915-ms","DOIUrl":"https://doi.org/10.2118/195915-ms","url":null,"abstract":"\u0000 Offshore field started on operation to produce crude oil with 27 API° as sweet crude and sour crude with 32 API° since 1960. Large number of wells in offshore field revealed undesirable phenomena related to well integrity issues as potentially sustained pressure on several casing strings. Well integrity management emphasis on preventing well problems related to well safety and integrity such as casing leak, Sustained Casing Pressure (SCP), downhole safety valve (DHSV) failures. The direct impact from integrity management added great value in terms of decreasing in operating down time, improvement in well control and safety aspects, and reducing unplanned repair intervention. In addition, the loss of well integrity can cause major accidents with a severe risk to the personnel, asset and environment.\u0000 The paper aims to illustrate a methodology results on applying effective well integrity monitoring techniques. A focus was made to improve monitoring well integrity through reviewing wellhead surface parameters, annulus sections pressure and downhole condition. In addition, the subject wells should be kept under close monitoring at a safe operable with an integral condition. Non-integral wells are common in aged wells, which are becoming a challenging issue to restore its integrity and operability especially for such aged completion. As a part of well integrity review, the concerns had been identified, investigated, and subsequently mitigations actions are recommended to restore the well integrity. Currently, it is confirmed that 25 oil producers with casing leak problems, which resulted to be converted from conventional completion to a slim hole with limited future accessblity. Based on lab reusltes and logging interpretations, it is indicated that the root cause of casing leaks is due to corrosive water flow from shallow aquifer formation. Therefore, an immediate remedial action is required to improve well construction.\u0000 A successful worked over well with integrity issue as a casing leak was repaired by cement squeeze into across the corroded casing interval, which enhanced well integrity and restore well productivity. The resulted showed that tubing leaks encountered with well integrity due to sustained casing pressure. Therefore, the pressure on production casing can cause severe failure with catastrophic damage. The results also illustrated that a water flow through poor cement is a major cause of sustained casing pressure in the outer casing strings. The cause of pressure on production casing is generally easier to diagnose than that pressure on one of the outer casing strings. Challenges, methodology, work schedule, risk assessment, lesson learned and findings are included in this paper. The effective well integrity management resulted on great deal of benefits, which are related to securing wells, well operability, cost saving, and sustained maximum production target.","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121823069","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":"Hydraulic Fracturing In Unconventional Reservoirs: The Impact of Layering and Permeable Frictional Interfaces","authors":"G. Qian, Ghassemi Ahmad","doi":"10.2118/195881-ms","DOIUrl":"https://doi.org/10.2118/195881-ms","url":null,"abstract":"\u0000 The hydraulic fracture containment and the impact of layering on pumping energy are critical factors in a successful stimulation treatment. Height confinement is needed to ensure effective stimulation of target zones and to maintain the fractures in the target zones. Also, the existence of beds with different ductility can impact the net pressure and pumping requirements. Layered rock properties, in-situ stress, and formations interfaces influence the lateral and height growth of hydraulic fractures. Conventionally, it is considered that the in-situ stress is the dominant factor controlling the fracture height. The influence of mechanical properties on fracture height growth is often ignored or is limited to consideration of different Young's modulus. Also, it is commonly assumed that the interfaces between different layers are perfectly bounded without slippage, and interface permeability is not considered. In-situ experiments have demonstrated that variation of modulus and in-situ stress alone cannot explain the containment of hydraulic fractures observed in field (SPE39950). Enhanced toughness, in-situ stress, interface slip and energy dissipation in the layered rocks should be combined to contribute to the fracture containment. In this study, we consider these factors in a fully coupled 3D hydraulic fracture simulator developed based on finite element method. We use laboratory and numerical simulations to investigate the above factors and how they impact hydraulic fracture propagation, height growth, and injection pressure.\u0000 In this work a 3D fully coupled hydro-mechanical model is developed and utilized. The model uses a special zero-thickness interface element and the cohesive zone model (CZM) to model fracture propagation, interface slippage, and fluid flow in fractures. The nonlinear mechanical behavior of frictional sliding along interface surfaces is considered. The hydro-mechanical model has been successfully verified through benchmarked analytical solutions. The influence of layered Young's modulus on fracture height growth in layered formations is analyzed. The formation interfaces between different layers are explicitly simulated through the usage of the hydro-mechanical interface element. The impacts of mechanical and hydraulic properties of the formation interfaces on preventing hydraulic fracture growth are studied.\u0000 Hydraulic fractures tend to propagate in the layer with lower Young's modulus so that soft layers could potentially act as barriers to limit the height growth of hydraulic fractures. Depending on the mechanical properties and the conductivity of the interfaces, the shear-slippage and/or opening along the formation interfaces could result in flow along the interface surfaces and terminate the fracture growth. The frictional slippage along the interfaces could be an effective mechanism that contributes to the containment of hydraulic fractures in layered formations. It is suggested that whether a hydraulic fracture w","PeriodicalId":325107,"journal":{"name":"Day 1 Mon, September 30, 2019","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126761539","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}