Experimental Study on the Effects of Pore Pressure and Slippage on the Permeability of a Fracture Network during Depressurization of Shale Gas Reservoir Production

Zhao, Hang; Li, Bing; Sun, Weiji; Hu, Zhiming; Sun, Jiaqi; Hao, Jianfeng; Liu, Qi

doi:10.1021/acsomega.1c07191

Cited by 7 publications

(5 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The apparent permeability of the shale samples is related to the pore pressure as a power function. The expression for pore pressure in the regression equation was obtained by fitting the relationship between permeability and pore pressure (Zhao et al ., 2022). After clarifying the specific expressions for each of the above physical parameters a multivariate nonlinear regression model was developed as follows:…”

Section: Optimization Model Of Multivariate Nonlinear Regression Anal...mentioning

confidence: 99%

Multivariate nonlinear regression analysis of hydraulic fracturing parameters based on hybrid FEM–DEM

Li,

Lan

2023

View full text Add to dashboard Cite

PurposeThis paper aims to employ a multivariate nonlinear regression analysis to establish a predictive model for the final fracture area, while accounting for the impact of individual parameters.Design/methodology/approachThis analysis is based on the numerical simulation data obtained, using the hybrid finite element–discrete element (FE–DE) method. The forecasting model was compared with the numerical results and the accuracy of the model was evaluated by the root mean square (RMS) and the RMS error, the mean absolute error and the mean absolute percentage error.FindingsThe multivariate nonlinear regression model can accurately predict the nonlinear relationships between injection rate, leakoff coefficient, elastic modulus, permeability, Poisson’s ratio, pore pressure and final fracture area. The regression equations obtained from the Newton iteration of the least squares method are strong in terms of the fit to the six sensitive parameters, and the model follow essentially the same trend with the numerical simulation data, with no systematic divergence detected. Least absolutely deviation has a significantly weaker performance than the least squares method. The percentage contribution of sensitive parameters to the final fracture area is available from the simulation results and forecast model. Injection rate, leakoff coefficient, permeability, elastic modulus, pore pressure and Poisson’s ratio contribute 43.4%, −19.4%, 24.8%, −19.2%, −21.3% and 10.1% to the final fracture area, respectively, as they increased gradually. In summary, (1) the fluid injection rate has the greatest influence on the final fracture area. (2)The multivariate nonlinear regression equation was optimally obtained after 59 iterations of the least squares-based Newton method and 27 derivative evaluations, with a decidability coefficient R2 = 0.711 representing the model reliability and the regression equations fit the four parameters of leakoff coefficient, permeability, elastic modulus and pore pressure very satisfactorily. The models follow essentially the identical trend with the numerical simulation data and there is no systematic divergence. The least absolute deviation has a significantly weaker fit than the least squares method. (3)The nonlinear forecasting model of physical parameters of hydraulic fracturing established in this paper can be applied as a standard for optimizing the fracturing strategy and predicting the fracturing efficiency in situ field and numerical simulation. Its effectiveness can be trained and optimized by experimental and simulation data, and taking into account more basic data and establishing regression equations, containing more fracturing parameters will be the further research interests.Originality/valueThe nonlinear forecasting model of physical parameters of hydraulic fracturing established in this paper can be applied as a standard for optimizing the fracturing strategy and predicting the fracturing efficiency in situ field and numerical simulation. Its effectiveness can be trained and optimized by experimental and simulation data, and taking into account more basic data and establishing regression equations, containing more fracturing parameters will be the further research interests.

show abstract

Section: Optimization Model Of Multivariate Nonlinear Regression Anal...mentioning

confidence: 99%

Multivariate nonlinear regression analysis of hydraulic fracturing parameters based on hybrid FEM–DEM

Li,

Lan

2023

View full text Add to dashboard Cite

show abstract

“…The examination revealed highly biomineralized by-products indicative of a shallow marine environment, including fossils fragments, carbonate sediments, and surrounding cement muds. The predominance of micrite cement suggests a relatively quiet depositional environment, while the bivalves and gastropods point to limited water conditions observed in both microfacies [58,59]. The presence of bioclasts such as bivalve shells and other skeletal fragments indicates a moderately saline shallow marine environment.…”

Section: Microfacies Analysis and Petrographic Descriptionmentioning

confidence: 99%

Unveiling the Diagenetic and Mineralogical Impact on the Carbonate Formation of the Indus Basin, Pakistan: Implications for Reservoir Characterization and Quality Assessment

Memon,

Tunio,

Memon

et al. 2023

Minerals

View full text Add to dashboard Cite

The Chiltan formation is a potential hydrocarbon-producing reservoir in the Indus Basin, Pakistan. However, its diagenetic alterations and heterogeneous behavior lead to significant challenges in accurately characterizing the reservoir and production performance. This manuscript aims to utilize six carbonate core samples of the Chiltan limestone to conduct an in-depth analysis of the diagenetic impacts on reservoir quality. The comprehensive formation evaluation was carried out through thin-section analysis, SEM-EDS, and FTIR investigation, as well as plug porosity and permeability measurements under varying stress conditions. In result, petrography revealed three microfacies of intraclastic packestone (MF1), bioclastic pelliodal packestone (MF2), and bioclastic ooidal grainstone (MF3), with distinct diagenetic features and micro-nano fossil assemblages. The MF1 microfacies consist of bioclasts, ooids, pellets, and induced calcite, while the MF2 microfacies contain micrite cemented peloids, algae, and gastropods. Although, the MF3 grainstone microfacies contains key features of bioclasts, milliods, bivalves, echinoderms, and branchiopods with intense micritization. Diagenesis has a significant impact on petrophysical properties, leading to increased reservoir heterogeneity. The specified depositional environment exposed the alteration of the Chiltan formation during distinct diagenetic phases in marine, meteoric, and burial settings. Marine diagenesis involves biogenic carbonates and micro-nano fossils, while meteoric diagenesis involves mineral dissolution, reprecipitation, secondary porosity, compaction, cementation, and stylolite formation. Pore morphology and mineralogy reveal a complex pore network within the formation, including a micro-nano pore structure, inter–intra particle, moldic, vuggy, and fenestral pores with variations in shape, connectivity, and distribution. Various carbonate mineral phases in the formation samples were analyzed, including the calcite matrix and dolomite crystals, while silica, calcite, and clay minerals were commonly observed cement types in the analysis. The core samples analyzed showed poor reservoir quality, with porosity values ranging from 2.02% to 5.31% and permeability values from 0.264 mD to 0.732 mD, with a standard deviation of 1.21. Stress sensitivity was determined using Klinkenberg-corrected permeability at increasing pore pressure conditions, which indicated around 22%–25% reduction in the measured gas permeability and 7% in Klinkenberg permeability due to increasing the net confining stress. In conclusion, the Chiltan formation possesses intricate reservoir heterogeneity and varied micropore structures caused by diagenesis and depositional settings. The formation exhibits nonuniform pore geometry and low petrophysical properties caused by the diverse depositional environment and various minerals and cement types that result in a low-quality reservoir. Stress sensitivity further decreases the permeability with varying stress levels, emphasizing the need of stress effects in reservoir management. The results of this study provide a solid foundation in reservoir characterization and quality assessment that has implications for predicting fluid flow behavior, providing insight into geological evolution and its impact on reservoir quality and leading to improving resource exploration and production strategies.

show abstract

“…Hydraulic fracturing is a fundamental production enhancement measure to transform low-permeability coal reservoirs. , The production enhancement effect of hydraulic fracturing in CBM wells depends on the reservoir modification area and fracture conductivity, , and the optimization of proppant performance, especially the selection of its type, size, and concentration, is crucial. , At present, quartz sand, ceramsite, and coated proppant are mainly used in hydraulic fracturing . Quartz sand is the most widely used proppant material in the fracturing process .…”

Section: Introductionmentioning

confidence: 99%

Coalbed Methane Enhancement in Low-Permeability Reservoirs by Hydraulic Fracturing with Coated Ceramsite

Guo

Song

et al. 2023

Energy Fuels

View full text Add to dashboard Cite

The overall fracturing stimulation effect using quartz sand as a proppant is poor, resulting in no breakthrough in the production of coalbed methane (CBM) wells in the low permeability coal reservoir of Lu’an Mining Area. In this study, the mixed coated ceramsite of three particle sizes (40–60, 16–40, and 12–20 mesh) was selected as a proppant to conduct a hydraulic fracturing field experiment on CBM wells, located near the three wells fractured with quartz sand in the study area. The drainage and production effects of mixed particle size-coated ceramsite and quartz sand fractured wells in the area were compared. The results show that the cumulative gas production from the coated ceramsite fractured CBM well was approximately 93,004 m3 in 238 days of gas production, with a maximum daily gas production of 825 m3/d, approximately 3.3 times that of the quartz sand fractured wells. After 400 days of gas production, the two types of proppant-fractured CBM wells differed notably, the daily gas production of the coated ceramsite-fractured well being 450–825 m3/d and that of the quartz sand-fractured wells being only 150–250 m3/d. In the stable production stage, the coated ceramsite-fractured well displayed a better gas production potential. Therefore, in view of the low permeability of the coal reservoir, the use of coated ceramsite to fracture CBM wells can achieve a more satisfactory production enhancement effect. The research findings can provide a reference for fracturing-induced production enhancement of low-permeability reservoirs.

show abstract

Experimental Study on the Effects of Pore Pressure and Slippage on the Permeability of a Fracture Network during Depressurization of Shale Gas Reservoir Production

Cited by 7 publications

References 35 publications

Multivariate nonlinear regression analysis of hydraulic fracturing parameters based on hybrid FEM–DEM

Multivariate nonlinear regression analysis of hydraulic fracturing parameters based on hybrid FEM–DEM

Unveiling the Diagenetic and Mineralogical Impact on the Carbonate Formation of the Indus Basin, Pakistan: Implications for Reservoir Characterization and Quality Assessment

Coalbed Methane Enhancement in Low-Permeability Reservoirs by Hydraulic Fracturing with Coated Ceramsite

Contact Info

Product

Resources

About