Pore Structure Characterization and the Controlling Factors of the Bakken Formation

The Bakken Formation is a typical tight oil reservoir and oil production formation in the world. Pore structure is one of the key factors that determine the accumulation and production of the hydrocarbon. In order to study the pore structures and main controlling factors of the Bakken Formation, 12 samples were selected from the Bakken Formation and conducted on a set of experiments including X-ray diffraction mineral analysis (XRD), total organic carbon (TOC), vitrinite reflectance (R o ), and low-temperature nitrogen adsorption experiments. Results showed that the average TOC and R o of Upper and Lower Bakken shale is 10.72 wt% and 0.86%, respectively. The Bakken Formation develops micropores, mesopores, and macropores. However, the Upper and Lower Bakken shale are dominated by micropores, while the Middle Bakken tight reservoir is dominated by mesopores. The total pore volume and specific surface area of the Middle Bakken are significantly higher than those of the Upper and Lower Bakken, indicating that Middle Bakken is more conducive to the storage of oil and gas. Through analysis, the main controlling factors for the pore structure of the Upper and Lower Bakken shale are TOC and maturity, while those for Middle Bakken are clay and quartz contents.

[1]  T. Gentzis,et al.  Organofacies study of the Bakken source rock in North Dakota, USA, based on organic petrology and geochemistry , 2018 .

[2]  R. Marc Bustin,et al.  Characterization of gas shale pore systems by porosimetry, pycnometry, surface area, and field emission scanning electron microscopy/transmission electron microscopy image analyses: Examples from the Barnett, Woodford, Haynesville, Marcellus, and Doig units , 2012 .

[3]  K. Sing.  Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity (Recommendations 1984) , 1985 .

[4]  M. Ostadhassan,et al.  Pore characterization of 3D-printed gypsum rocks: a comprehensive approach , 2018, Journal of Materials Science.

[5]  L. Ter-minassian-saraga.  PHYSICAL CHEMISTRY DIVISION COMMISSION ON COLLOID AND SURFACE CHEMISTRY , 2005 .

[6]  Javier Pérez-Ramírez,et al.  Pore size determination in modified micro- and mesoporous materials. Pitfalls and limitations in gas adsorption data analysis , 2003 .

[7]  B. Hart,et al.  Characterizing the Middle Bakken: Laboratory Measurement and Rock Typing of the Middle Bakken Formation , 2015 .

[8]  Ruobing Liu,et al.  Characteristics and controlling factors of micropore structures of the Longmaxi Shale in the Jiaoshiba area, Sichuan Basin , 2014 .

[9]  Janet K. Pitman,et al.  Diagenesis and fracture development in the Bakken Formation, Williston Basin; implications for reservoir quality in the middle member , 2001 .

[10]  F. Schüth,et al.  Direct imaging of surface topology and pore system of ordered mesoporous silica (MCM-41, SBA-15, and KIT-6) and nanocast metal oxides by high resolution scanning electron microscopy. , 2008, Journal of the American Chemical Society.

[11]  Bo Zhang,et al.  The determination of variogram in the presence of horizontal wells - An application to a conglomerate reservoir modeling, East China , 2019, Journal of Petroleum Science and Engineering.

[12]  Jianchao Cai,et al.  An improved model for estimating the TOC in shale formations , 2017 .

[13]  D. Avnir,et al.  Recommendations for the characterization of porous solids (Technical Report) , 1994 .

[14]  R. Bustin,et al.  Lithofacies and paleoenvironments of the Upper Devonian and Lower Mississippian Bakken Formation, Williston Basin , 1996 .

[15]  L. Sandoval-Díaz,et al.  Fractal analysis at mesopore scale of modified USY zeolites by nitrogen adsorption: A classical thermodynamic approach , 2017 .

[16]  Ning Zhao,et al.  Pore Structure Characterization of the Tight Reservoir: Systematic Integration of Mercury Injection and Nuclear Magnetic Resonance , 2018, Energy & Fuels.

[17]  Ke Ma,et al.  OVERALL PSD AND FRACTAL CHARACTERISTICS OF TIGHT OIL RESERVOIRS: A CASE STUDY OF LUCAOGOU FORMATION IN JUNGGAR BASIN, CHINA , 2019, Fractals.

[18]  J. Sarg,et al.  Bakken Mudrocks of the Williston Basin, World Class Source Rocks* , 2011 .

[19]  M. Jaroniec,et al.  Application of large pore MCM-41 molecular sieves to improve pore size analysis using nitrogen adsorption measurements , 1997 .

[20]  M. Titirici,et al.  The influence of pore size distribution on the oxygen reduction reaction performance in nitrogen doped carbon microspheres , 2016 .

[21]  F. Meissner.  Petroleum Geology of the Bakken Formation Williston Basin, North Dakota and Montana , 1991 .

[22]  Jianchao Cai,et al.  Estimating thermal maturity of organic-rich shale from well logs: Case studies of two shale plays , 2019, Fuel.

[23]  T. Gentzis,et al.  Nanomechanical characterization of organic matter in the Bakken formation by microscopy-based method , 2018, Marine and Petroleum Geology.

[24]  Y. Liu,et al.  Pore characteristic analysis of a lacustrine shale: A case study in the Ordos Basin, NW China , 2016 .

[25]  Mehdi Ostadhassan,et al.  Nanoscale pore structure characterization of the Bakken shale in the USA , 2017 .

[26]  Jun Li,et al.  Mineral and pore structure characteristics of gas shale in Longmaxi formation: a case study of Jiaoshiba gas field in the southern Sichuan Basin, China , 2016, Arabian Journal of Geosciences.

[27]  Xiangyun Hu,et al.  FRACTAL CHARACTERIZATION OF DYNAMIC FRACTURE NETWORK EXTENSION IN POROUS MEDIA , 2017 .

[28]  M. Ostadhassan,et al.  Fractal and Multifractal Characteristics of Pore Throats in the Bakken Shale , 2018, Transport in Porous Media.

[29]  Zheng Min,et al.  Assessment criteria,main types,basic features and resource prospects of the tight oil in China , 2012 .

[30]  J. Verweij.  Hydrocarbon Migration Systems Analysis , 1993 .

[31]  Feng Yang,et al.  Fractal characteristics of shales from a shale gas reservoir in the Sichuan Basin, China , 2014 .

[32]  Zhenxue Jiang,et al.  The effects of shale pore structure and mineral components on shale oil accumulation in the Zhanhua Sag, Jiyang Depression, Bohai Bay Basin, China , 2018, Journal of Petroleum Science and Engineering.

[33]  R. Webster.  Petroleum Source Rocks and Stratigraphy of Bakken Formation in North Dakota: ABSTRACT , 1984 .

[34]  Dongfeng Hu,et al.  Applying SANS technique to characterize nano-scale pore structure of Longmaxi shale, Sichuan Basin (China) , 2017 .

[35]  D. Wood,et al.  Characterization of organic-rich shales for petroleum exploration & exploitation: A review-Part 1: Bulk properties, multi-scale geometry and gas adsorption , 2017, Journal of Earth Science.

[36]  M. Ostadhassan,et al.  Quantification of the microstructures of Bakken shale reservoirs using multi-fractal and lacunarity analysis , 2017 .

[37]  A. Varma,et al.  Organo-petrographic and pore facets of Permian shale beds of Jharia Basin with implications to shale gas reservoir , 2017, Journal of Earth Science.

[38]  E. Teller,et al.  ADSORPTION OF GASES IN MULTIMOLECULAR LAYERS , 1938 .

[39]  Suihong Song,et al.  Combining pressure-controlled porosimetry and rate-controlled porosimetry to investigate the fractal characteristics of full-range pores in tight oil reservoirs , 2018, Journal of Petroleum Science and Engineering.

[40]  Luo Xingping,et al.  Study on the response mechanisms of nuclear magnetic resonance(NMR)log in tight oil reservoirs , 2016 .

[41]  Boming Yu,et al.  Fractal analysis of invasion depth of extraneous fluids in porous media , 2010 .

[42]  Z. Wang,et al.  Transmission Electron Microscopy of Shape-Controlled Nanocrystals and Their Assemblies , 2000 .

[43]  J. Parlange.  Porous Media: Fluid Transport and Pore Structure , 1981 .

[44]  E. Barrett,et al.  (CONTRIBUTION FROM THE MULTIPLE FELLOWSHIP OF BAUGH AND SONS COMPANY, MELLOX INSTITUTE) The Determination of Pore Volume and Area Distributions in Porous Substances. I. Computations from Nitrogen Isotherms , 1951 .

[45]  Wei Xiang-fen.  Micro-pores Structure Characteristics and Development Control Factors of Shale Gas Reservoir:A Case of Longmaxi Formation in XX Area of Southern Sichuan and Northern Guizhou , 2013 .

[46]  Jeff Gelb,et al.  Multi-scale method of Nano(Micro)-CT study on microscopic pore structure of tight sandstone of Yanchang Formation, Ordos Basin , 2013 .