Impact of Capillary Pressure and Critical Property Shift due to Confinement on Hydrocarbon Production in Shale Reservoirs

Abstract

This thesis marks the end of a great chapter of my life and the beginning of several stellar possibilities. My two years at Stanford have changed my life and the knowledge I have gained will certainly brighten my future paths like never before. My thanks to Energy Resources Engineering, Reservoir Simulation Industrial Affiliates (SUPRI-B) program and ENI for funding my MS and Stanford Summer Tutorial program which gave me one of the best experiences of lecturing Stanford students in my final quarter of MS. I would like to thank Dr. Khalid Aziz who accepted me as his student and guided me throughout this research. To have worked with him was such a great privilege. When I had come to Stanford, I may not have been the best student in our batch, but towards the beginning of my second year, I was well determined to produce one of the best MS theses submitted in our year. I would like to thank Denis Voskov, who is extremely knowledgeable and his suggested directions were very important to my research. My heartfelt thanks to Dr. Huanquan for his great tips and advices, which made me redo my results over and over again. I am very grateful to Sergey Klevtsov, who was the one you actually got be started with AD-GPRS. My initial progress with AD-GPRS would not have been so rapid had it not been for him. Finally I would like to thank Sergey Chaynikov for the many hours he spent listening to my issues and advising me about the possible strategies to ponder over. He has always been available on just an email of mine. I would also love to mention some of the awesome people I met at Stanford-my office mates and other friends which include

Phase behavior of hydrocarbons in nano-pores

“…Saturated bulk pressure and saturated confined pressure are often compared in the literature in studies using EOS modification by critical point shift [14,16,20,23,25,26,27] or capillary pressure method [14,15,16,17,18,19,20,21,22]. Comparison between classic EOS and modified EOS for confined fluid modeling showed that the bubble point pressure decreases with confinement.…”

“…Secondly, a lot of work has been done on extension of equations of state (EOS) for confined fluid behavior modeling. The first main method used includes capillary pressure in the flash calculation considering two phases in equilibrium having two different pressures [14,15,16,17,18,19,20,21,22]. Some authors improve this method by considering the thickness of the adsorbed layer [23,24].…”

“…Some authors improve this method by considering the thickness of the adsorbed layer [23,24]. The second main method takes into account a unique pressure for both phases and adds shift of critical temperature and pressure in the flash calculation [14,16,20,23,25,26,27]. The correlations used for critical temperature and pressure versus pore radius are either analytical [28] or built from molecular simulation results [26,27].…”

Impact of fluid property shift and capillarity on the recovery mechanisms of CO2injection in tight oil reservoirs

“…The cubic EOS that uses pressure–volume–temperature (PVT) is widely used to describe fluid properties, such as Van der Waals EOS, Soave modification of Redlich–Kwong (SRK), Peng–Robinson (PR) EOS, et al . The PR EOS exhibits performance similar to that of the SRK equation for the most part, and the SRK EOS has been used to study the confinement effect in this paper, and has been widely used for oil reservoir simulation tools . The parameters are generally determined by the physical laboratory measurements (such as PVT cell) using the bulk fluid.…”

“…The cubic EOS that uses pressure-volume-temperature (PVT) is widely used to describe fluid properties, such as Van der Waals EOS, Soave modification of Redlich-Kwong (SRK), Peng-Robinson (PR) EOS, et al [7][8][9][10] The PR EOS exhibits performance similar to that of the SRK equation for the most part, and the SRK EOS has been used to study the confinement effect in this paper, and has been widely used for oil reservoir simulation tools. [11][12][13][14] The parameters are generally determined by the physical laboratory measurements (such as PVT cell) using the bulk fluid. Besides, the SRK EOS introduces the interaction factor of fluid molecules and ignores the molecular-wall collision factor, which means that it should be improved for it to be applied for numerical simulation of tight oil reservoir development.…”