Unconventional Resources最新文献

{"title":"The present-day in-situ stress field and its effect on shale gas development in Zigong area of southern Sichuan Basin","authors":"Weike Ning ,&nbsp;Wei Ju ,&nbsp;Wei Guo","doi":"10.1016/j.uncres.2024.100078","DOIUrl":"https://doi.org/10.1016/j.uncres.2024.100078","url":null,"abstract":"<div><p>The Zigong area in southern Sichuan Basin is one of the key shale gas production areas in China, and the Longmaxi and Wufeng Formations within it are currently the key exploration and development layers. The present-day <em>in-situ</em> stress field has a significant impact on well trajectory deployment, horizontal well construction, hydraulic fracturing and other aspects. However, it has not been finely quantified in shale gas reservoirs of Zigong area, making it difficult to effectively guide development practice. Therefore, this study constructed a geomechanical model of the target layer in the Zigong area, quantitatively characterized the distribution of present-day <em>in-situ</em> stress, and explored its shale gas development effects. The results show that: (1) Based on the analysis of drilling induced fractures obtained from rock acoustic emission experiments and imaging logging interpretation, the dominant orientation of the maximum horizontal principal stress in the target layer is mainly NW-SE-trending; (2) The horizontal principal stress difference in the Layer S₁<em>l</em>^1-1−1 and Wufeng Formation is 5–30 MPa (the majority is 6–15 MPa) and 5–35 MPa (the majority is 6–18 MPa), respectively. Low stress difference values are mainly concentrated in the southeastern and northern parts. The overall prediction accuracy is high, with an error rate of less than 8% for the Layer S₁<em>l</em>^1-1−1 and less than 10% for the Wufeng Formation; (3) Based on rock acoustic emission experiments and finite element model simulation results, the study area is mainly under strike-slip stress faulting mechanism; (4) Due to the influence of the strike-slip faulting stress mechanism, when deploying horizontal wells in the area, priority should be given to selecting areas with low stress mechanism factor (<em>A</em>_φ) and low stress differences, to achieve better fracturing and transformation effects and reduce the risk of casing deformation and wellbore instability.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100078"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000062/pdfft?md5=8bc677dbb460b21e5746be2ff7aa5acc&pid=1-s2.0-S2666519024000062-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139976060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geothermal resource estimation of Uttarakhand region, India","authors":"Namrata Bist,&nbsp;Raiwant Modh,&nbsp;Tithee Bhavsar,&nbsp;Anirbid Sircar","doi":"10.1016/j.uncres.2024.100094","DOIUrl":"https://doi.org/10.1016/j.uncres.2024.100094","url":null,"abstract":"<div><p>With many countries dependent on imported fuels, governments and industries are diversifying energy sources, including geothermal energy. Geothermal energy, derived from the Earth's internal heat, holds significant potential as a renewable energy source. The present work focuses on the geothermal resource estimation of the Uttarakhand region in India. Critical subsurface reservoir parameters for geothermal extraction and estimates of potential resources are reviewed through an analysis of geological formations, temperature gradients, and rock permeability. Various estimation methods, including surface heat flux, volume methods, and probabilistic methods, are discussed, with a particular emphasis on the Monte Carlo method. Assessment of the resource potential of the Uttarakhand geothermal system using available data estimates the resource potential of the Uttarakhand prospect, revealing an energy estimate of 1.26*10^15 J/kg (P50 case). Correspondingly, for the P90 and P10 scenarios, the estimated heat stands at 2.30*10^15 J/kg and 2.6*10^14 J/kg, respectively<strong>.</strong> However, successful exploitation requires a thorough understanding of subsurface reservoir parameters and careful resource estimation. This comprehensive analysis offers valuable insights for policymakers, researchers, and industry stakeholders interested in harnessing geothermal energy for sustainable development.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100094"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000220/pdfft?md5=6927e945d749169dabe8937531a4be76&pid=1-s2.0-S2666519024000220-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140905414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bayesian variable pressure decline-curve analysis for shale gas wells","authors":"Leopoldo M. Ruiz Maraggi ,&nbsp;Mark P. Walsh ,&nbsp;Larry W. Lake ,&nbsp;Frank R. Male","doi":"10.1016/j.uncres.2024.100103","DOIUrl":"10.1016/j.uncres.2024.100103","url":null,"abstract":"<div><p>Decline-curve analysis and production forecasting are usually performed from a deterministic standpoint (point estimation). This approach does not quantify the uncertainty of the model's parameters and thus, the model's estimated ultimate recovery. In addition, decline-curve models do not consider the variations in the bottomhole flowing pressure, which can greatly impact the accuracy of the model's predictions. This work combines a new technique that incorporates variable bottomhole flowing pressure conditions into decline-curve models with Bayesian inference to improve the accuracy of production history-matches while quantifying the uncertainty of the model's parameters and its future production prediction. The method provides fast production history-matches and forecasts of shale gas wells (taking around 1 min per well) and it is more accurate than traditional decline-curve analysis for wells subject to variable bottomhole flowing pressure conditions while quantifying the uncertainty in the model's parameters and estimated ultimate recovery. The main contribution of this work is the illustration of a new method for probabilistic variable pressure decline-curve analysis. We present the application of this workflow for shale gas wells.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100103"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000311/pdfft?md5=485586fb7540f46c791ccdccd52dd39b&pid=1-s2.0-S2666519024000311-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141978463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation of thermal performance of H2O-EGS and CO2-EGS based on thermal-hydraulic-mechanical coupling method","authors":"Bin Liu ,&nbsp;Chunyang Feng ,&nbsp;Xiaofei Fu","doi":"10.1016/j.uncres.2024.100106","DOIUrl":"10.1016/j.uncres.2024.100106","url":null,"abstract":"<div><p>The use of hydrothermal geothermal methods in Enhanced Geothermal Systems (EGS) presents challenges like reduced thermal storage life and high external energy consumption. Due to its stable heat production time and lower external energy demand, CO₂ has the potential to be substituted for H₂O. The research zone for this study was chosen to be located in the HDR reservoir in the Gonghe Basin of Qinghai. A three-dimensional discrete fracture model based on a thermal-hydraulic-mechanical coupling method is established, where numerical simulations are conducted using COMSOL software. The discussion focuses on the comparison of heat production effects between H₂O-EGS and CO₂-EGS in different injection and extraction scenarios are discussed. The results indicate that by lowering the injection temperature and increasing the injection rate, the EGS net heat production rate can be increased, but it also accelerates the heat breakthrough time and shortens the reservoir life. Although CO₂-EGS has a lower heat extraction rate in the early stage of thermal recovery than H₂O-EGS, it has a longer stable heat production time and a more energy-efficient heat production process. Therefore, compared to H₂O-EGS, CO₂-EGS has more economic and social benefits.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100106"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000347/pdfft?md5=fc02d32b3e02fb29a7b142154eb2a958&pid=1-s2.0-S2666519024000347-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142173909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microscopic pore-throat classification and reservoir grading evaluation of the Fengcheng formation in shale oil reservoir","authors":"Hong-jiao Tang ,&nbsp;Gen Kou ,&nbsp;Hao Zhou ,&nbsp;Wen-wen Liu ,&nbsp;Xin-guo Duan ,&nbsp;Shi-yuan Zhan ,&nbsp;Hai-yue Li ,&nbsp;Quan-zhen Li","doi":"10.1016/j.uncres.2024.100074","DOIUrl":"https://doi.org/10.1016/j.uncres.2024.100074","url":null,"abstract":"<div><p>Different basins in China have proposed various reservoir grading standards for shale oil. Based on a comprehensive understanding of the basic characteristics of the shale oil reservoir in the Mahu Depression, this paper uses data from high-pressure mercury injection, physical properties, nuclear magnetic resonance, depletion development, and CO₂ displacement development tests to analyze the microscopic pore structure features of the Fengcheng Formation shale oil reservoir. On this basis, the classification boundaries of the pore throats in the shale oil reservoir were analyzed, and a reservoir grading standard suitable for the Fengcheng Formation shale was proposed: large pore throats (greater than 1000 nm), medium pore throats(100∼1000 nm), small pore throats (20∼100 nm), and ultra-small pore throats (less than 20 nm). The medium pore throat is the lower limit for depletion development, the small pore throat is the lower limit under CO₂ displacement conditions, and the ultra-small pore throat cannot be utilized under current conditions. The classification effect of the shale oil reservoir is verified using the production characteristics of Well MY1, the liquid production profile, and the results of geological \"sweet spots\" studies. The results show that the classification scheme for the microscopic pore throats of the Fengcheng Formation shale oil is reliable and feasible.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100074"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000025/pdfft?md5=6111e3c5da6be7c2e4197acf4debf217&pid=1-s2.0-S2666519024000025-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139503366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Suppressing solar PV output fluctuations by designing an efficient hybrid energy storage system controller","authors":"Mohammadreza Moghadam,&nbsp;Navid Ghaffarzadeh","doi":"10.1016/j.uncres.2024.100077","DOIUrl":"https://doi.org/10.1016/j.uncres.2024.100077","url":null,"abstract":"<div><p>The stochastic nature of solar photovoltaics (PV), marked by high-frequency voltage fluctuations due to dynamic climatic conditions such as cloud cover and temperature variations, presents a significant challenge to power quality stability, especially in microgrids. This variability poses a threat to the stability of power electronic devices responsible for power control and monitoring, potentially compromising the power grid's stability. To address this challenge, energy storage systems (ESS) are commonly employed. In this study, we develop a hybrid energy storage system (HESS) incorporating a battery, supercapacitor, and fuel cell. The primary aim is to adjust the inverter voltage for the photovoltaic system using newly developed proportional-integral (PI) and model predictive control (MPC) controllers within the HESS framework. Importantly, this controller eliminates the need for precise knowledge of system parameters and offers robustness, insensitivity to parameter changes, and resilience to time-varying external disturbances, ensuring satisfactory performance. By mitigating power fluctuations, the generated power can be seamlessly integrated into the grid, significantly reducing costs associated with device damage in the power path.</p><p>Notably, we integrate the proposed photovoltaic system with an RLC series load using an IGBT inverter. To assess the performance of the HESS in the proposed photovoltaic system, four distinct scenarios are examined. These scenarios involve altering the PV system's location and testing two energy storage systems, namely the battery and fuel cell, which are separately designed components of the HESS for a 14-bus microgrid.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100077"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000050/pdfft?md5=701a49ceb8cb92a00b10aa6ad2f64044&pid=1-s2.0-S2666519024000050-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140290932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recycled waste groundnut oil: A potential feedstock for green energy/biodiesel synthesis","authors":"Christian O. Asadu ,&nbsp;Benjamin Nnamdi Ekwueme ,&nbsp;Chinonso Anthony Ezema ,&nbsp;Thomas O. Onah ,&nbsp;Innocent Sunday Ike ,&nbsp;Judith Obioma Ugwuele ,&nbsp;Chikezie Christian Aka ,&nbsp;Onoh Ikechukwu Maxwell ,&nbsp;Emmanuel O. Umeagukwu ,&nbsp;Churchill Chisom Ogbonna","doi":"10.1016/j.uncres.2024.100081","DOIUrl":"https://doi.org/10.1016/j.uncres.2024.100081","url":null,"abstract":"<div><p>This work focuses on the recycling of waste groundnut oil as a potential feedstock for biodiesel production using activated coconut husk as a regenerating agent. The coconut husk was functionalized using organic acid. The properties of the functionalized coconut husk were investigated via instrumental analysis. Non-parametric modeling involving 2-degree isotherm models were used. The regeneration/recycling of the waste oil were done in batch mode examining key factors of temperature, time, concentration and dosage. Biodiesel was synthesized from recycled waste groundnut oil using transesterification reaction. The properties of biodiesel were examined using ASTM and AOAC official standards. Brunauer-Emmett-Teller surface analysis revealed the surface area of the adsorbent as 371.88 m²/g and a porosity distribution of 0.567 <span><math><mrow><mi>η</mi></mrow></math></span> on the surface at a pH of 6.1. Batch mode analysis revealed that 97.5% of impurities was removed from waste groundnut oil under one batch process at 80 °C after 4 h with 6 g of the activated coconut husk. Langmuir isotherm model provided the best fit to the experimental data with adsorption capacity of 33.5 mg/g at R² of 0.996. Adsorption of waste groundnut oil impurities onto activated coconut husk was endothermic, as evidenced by the calculated ΔH of +2.7914 kJ/mol. A high cetane number of 48.4 obtained after transesterification is an indication of the good ignition quality of the obtained recycled waste groundnut oil methyl ester. Kinematic viscosity and acid value were revealed to be 4.65 mm² S⁻¹ and 0.31 mg KOH/g, while the calorific value stood at 38,053 kJ/kg. GC-MS analysis revealed a complex mixture of fatty acid methyl esters dominated by unsaturated fatty acids (58.78%). Recycling of waste cooking oil in this work using activated coconut husk demonstrated good quality as a regenerating agent. The properties of biodiesel obtained showed that it has all the good qualities comparable to other existing biodiesel based on the ASTM and AOAC official standards. More work on the recycling of other waste cooking oils for green energy synthesis to protect our environment from pollution emanating from the use of conventional petro-diesel and promote energy transition is highly recommended.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100081"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000098/pdfft?md5=e44754d193a7e1b8cd195e55f3d124ce&pid=1-s2.0-S2666519024000098-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140309424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developmental characteristics of fractures in deep tight sandstone reservoirs in the second Member of the Xujiahe Formation of Zhongjiang Gas Field","authors":"Wenli Cai ,&nbsp;Runcheng Xie ,&nbsp;Huaji Li ,&nbsp;Shiliang Dou ,&nbsp;Siyuan Li ,&nbsp;Shuanglin Deng ,&nbsp;Tingting Ma","doi":"10.1016/j.uncres.2024.100073","DOIUrl":"10.1016/j.uncres.2024.100073","url":null,"abstract":"<div><p>The development characteristics, scale and control factors of fractures are the core subjects of reservoir sweet spot prediction. The sandstone reservoir of the TX₂ gas reservoir in the Zhongjiang Gas Field is a typical low porosity and low permeability tight reservoir with strong heterogeneity, but relatively high-quality reservoirs can be found in different well areas and well segments. In this paper, taking the second Member of the Xujiahe Formation (TX₂) as an example, the control factors of fractures were systemically investigated via core observation, thin section, logging data, and fracture logging identifications. The results show that shear fractures are mainly developed in the cores, and they generally have high filling rate and poor effectiveness; microfractures can be found based on the vitrinite and cast thin section results. The intersection diagram (semi-quantitative) and the principal component and BP comprehensive identification (quantitative) methods can effectively identify different types of fractures. The combined application of principal component and BP comprehensive identification methods results in an 83.3 % fracture identification probability. Finally, we found that the development of fractures in TX₂ is comprehensively affected by lithology, rock thickness, porosity, and faults.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100073"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000013/pdfft?md5=878ca39ed51e18038394b43a690841ed&pid=1-s2.0-S2666519024000013-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139392356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heat production rate of deep rocks in Bohai Bay Basin and its relationship with terrestrial heat flow","authors":"Zhao Ma ,&nbsp;Chuanqing Zhu ,&nbsp;Kefu Li ,&nbsp;Chaohe Fang ,&nbsp;Qian Cao","doi":"10.1016/j.uncres.2023.100072","DOIUrl":"https://doi.org/10.1016/j.uncres.2023.100072","url":null,"abstract":"<div><p>The vertical distribution of rocks’ radioactive heat production rate in the continental crust is the basis for exploring the deep thermal structure and explaining terrestrial heat flow distribution characteristics. In this paper, taking the Bohai Bay Basin as an example, according to the content of U, Th and K in the rocks and the lithologic composition of each structural layer of the crust, calculating the range of radioactive heat-generating elements in each structural layer. Then, systematically analyze the distribution characteristics of heat production rate in the crust. Finally, establish the vertical distribution model of heat production rate and discuss the relationship between heat flow and heat production rate. The results show that the rock heat production rate is mainly related to lithology. U and Th are primarily enriched in the upper crust with exponential distribution, while K content is unchanged. Under exponential crustal heat production rate distribution, the D_U, D_Th and D_A in the crust are 15.195 km, 15.29 km and 21.11 km, respectively. A linear relationship exists between heat flow and heat production rate but cannot infer the thermal condition of the middle and lower crust.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100072"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519023000511/pdfft?md5=1c635c15543dd5fd9456afb121348c29&pid=1-s2.0-S2666519023000511-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139398800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Productivity drivers in North American tight and shale plays: A comprehensive analysis of completion trends, stimulation parameters, and geological characteristics","authors":"Harpreet Singh,&nbsp;Peng Cheng","doi":"10.1016/j.uncres.2024.100087","DOIUrl":"https://doi.org/10.1016/j.uncres.2024.100087","url":null,"abstract":"<div><p>This study evaluates the productivity of ten major unconventional oil and gas plays in North America, emphasizing the role of completion, stimulation, and geological factors. The primary objective is to thoroughly assess the influence of various completion, stimulation, and geological parameters on well productivity while uncovering key insights and emerging trends unique to each play.</p><p>The dataset comprises 72,809 horizontal wells from 2015 to 2022 across 10 plays, encompassing 6 oil plays (Bakken, Delaware, Duvernay, Midland, Eagle Ford, and Scoop|Stack) and 4 gas plays (Haynesville, Barnett, Marcellus, and Utica). This study examines completion and fracture stimulation trends influencing the productivity of various plays, along with the significance of geological and mechanical properties.</p><p>Key findings reveal that while geological characteristics, such as total organic carbon (TOC) content and brittleness, significantly impact reservoir quality, operational practices like completion design and stimulation techniques, also play critical roles in well productivity. Key insights from the analysis challenge the traditional emphasis on TOC as a sole productivity indicator, which might not be as pronounced as commonly assumed. The analysis indicates that, contrary to common beliefs, plays exhibiting both a lower brittleness index and fewer wells per pad are associated with faster fracture growth rates. Adding more wells per pad increases the minimum horizontal stress in the neighborhood, which slows fracture growth and causes it to redirect upward. Horizontal spacing plays a crucial role in enhancing productivity, especially in less productive plays which benefit from denser well development. Co-completion of wells leads to superior performance by reducing fracture-driven interactions or “frac hits”. While longer laterals increase resource contact, productivity gains are not linear. The productivity impact of increasing clusters per stage is variable, potentially limited by the stress shadowing effect.</p><p>In summary, this study offers critical insights into the productivity-influencing factors across diverse shale plays, contributing to the optimization of well development and resource extraction in the future. This study not only provides technical guidance for the unconventional oil and gas developments in North America, but can also serve as a valuable guide for similar projects elsewhere.</p></div>","PeriodicalId":101263,"journal":{"name":"Unconventional Resources","volume":"4 ","pages":"Article 100087"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666519024000153/pdfft?md5=c8466fc92a82e27161c59a2838563a40&pid=1-s2.0-S2666519024000153-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140823082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}