Upscale methodology for gas huff-n-puff process in shale oil reservoirs

Abstract Results of recent laboratory experiment studies suggest that huff-n-puff gas injection holds great potential to increase oil recovery from shale oil cores. However, our current knowledge of the field-scale performance of this process is very limited. Reservoir simulation is required to properly upscale this process from laboratory to field conditions in order to predict oil recovery and reduce the risk of failure in field projects. After examining the literature, the purpose of all upscale methods is to generate a single curve which can describe the relationship of oil recovery versus dimensionless time for different scales. For a gas huff-n-puff process applied in a shale oil reservoir, it is also necessary to generate one single type curve to upscale a lab experiment to field-scale production. In this paper a new expression of dimensionless pressure was generated to describe the huff-n-puff efficiency, and a new version of dimensionless time was also derived that includes dimensionless pressure, permeability, porosity, viscosity, and core length. A compositional numerical model with dynamic gridding was built and validated by matching the experimental data, and the model was then used to test the upscale methodology. Several validation tests were conducted for different fluid and rock parameters, well constraints, and operation schedules. To this end, a type curve was developed for different scales which demonstrates that all sizes yield a similar relationship between oil recovery and dimensionless operation time. It proves that the cumulative oil recovery of gas huff-n-puff EOR in shale oil reservoirs can be predicted. In a case of high-permeability, the curve between oil recovery and dimensionless time deviates from the type curve (moves to the right side). This indicates huff and puff times are too long, and the process is inefficient. In this case, the huff and puff times can be reduced so that the curve follows the generated type curve.

[1]  J. Sheng,et al.  Optimization of huff-n-puff gas injection in a shale gas condensate reservoir , 2016 .

[2]  L. Lake,et al.  Scaling Fluid Flow Through Heterogeneous Permeable Media , 1993 .

[3]  K. Sepehrnoori,et al.  A sensitivity study of potential CO2 injection for enhanced gas recovery in Barnett Shale reservoirs , 2014 .

[4]  Kamy Sepehrnoori,et al.  Simulation Study of CO2 Huff-n-Puff Process in Bakken Tight Oil Reservoirs , 2014 .

[5]  Yang Yu,et al.  An Experimental Investigation of the Effect of Pressure Depletion Rate on Oil Recovery from Shale Cores by Cyclic N2 Injection , 2015 .

[6]  Yang Yu,et al.  Experimental and numerical study of the EOR potential in liquid-rich shales by cyclic gas injection , 2015 .

[7]  J. Sheng,et al.  Experimental and numerical study of huff-n-puff gas injection to re-vaporize liquid dropout in shale gas condensate reservoirs , 2016 .

[8]  P. J. Griffith,et al.  Potential to increase condensate oil production by huff-n-puff gas injection in a shale condensate reservoir , 2016 .

[9]  Hossein Kazemi,et al.  Evaluation of Bakken Performance Using Coreflooding, Well Testing, and Reservoir Simulation , 2012 .

[10]  Kamy Sepehrnoori,et al.  Scale Up Methodology for Wettability Modification in Fractured Carbonates , 2009 .

[11]  J. Sheng,et al.  An Experimental Study of Cyclic Gas Injection to Improve Shale Oil Recovery , 2013 .

[12]  C. C. Mattax,et al.  Imbibition Oil Recovery from Fractured, Water-Drive Reservoir , 1962 .

[13]  J. Sheng,et al.  Compositional Modeling of the Diffusion Effect on EOR Process in Fractured Shale Oil Reservoirs by Gas Flooding , 2015 .

[14]  Alain C. Gringarten,et al.  A COMPARISON BETWEEN DIFFERENT SKIN AND WELLBORE STORAGE TYPE-CURVES FOR EARLY-TIME TRANSIENT ANALYSIS , 1979 .

[15]  Roland N. Horne,et al.  Generalized Scaling Approach for Spontaneous Imbibition: An Analytical Model , 2006 .

[16]  F. Kalaydjian,et al.  Oil recovery by imbibition in low-permeability chalk , 1994 .

[17]  J. Geertsma,et al.  Theory of Dimensionally Scaled Models of Petroleum Reservoirs , 1956 .

[18]  Mohamed Y. Soliman,et al.  Effect of Fracture Characteristics on Behavior of Fractured Shale-Oil Reservoirs by Cyclic Gas Injection , 2016 .

[19]  D. Zhou,et al.  An Investigation of Counter-Current Imbibition Processes in Diatomite , 2001 .

[20]  Roland N. Horne,et al.  A General Scaling Method for Spontaneous Imbibition , 2002 .

[21]  Larry W. Lake,et al.  A Screening Model for CO 2 Flooding and Storage in Gulf Coast Reservoirs Based on Dimensionless Groups , 2006 .

[22]  P. H. Sammon,et al.  Dynamic Grid Refinement and Amalgamation for Compositional Simulation , 2003 .

[23]  Yang Yu,et al.  An Experimental Study on Huff-n-Puff Gas Injection to Enhance Condensate Recovery in Shale Gas Reservoirs , 2015 .

[24]  Hoffman B. Todd,et al.  Improved Oil Recovery IOR Pilot Projects in the Bakken Formation , 2016 .

[25]  T. C. Boberg,et al.  Scaling Accuracy of Laboratory Steam Flooding Models , 1972 .

[26]  T. Wan.  Evaluation of the EOR potential in shale oil reservoirs by cyclic gas injection , 2013 .

[27]  Generalized Scaling Of Spontaneous Imbibition Data For Strongly Water-Wet Systems , 1995 .

[28]  Lei Li,et al.  Optimization of Huff-n-Puff Gas Injection to Enhance Oil Recovery in Shale Reservoirs , 2016 .

[29]  L. L. Handy.  Determination of Effective Capillary Pressures for Porous Media from Imbibition Data , 1960 .

[30]  J. Sheng.  Increase liquid oil production by huff-n-puff of produced gas in shale gas condensate reservoirs , 2015 .

[31]  J. Sheng,et al.  Enhanced Recovery of Crude Oil From Shale Formations by Gas Injection in Zipper-fractured Horizontal Wells , 2015 .

[32]  Mohamed Y. Soliman,et al.  An Experimental Study of Cyclic CO2 Injection to Improve Shale Oil Recovery , 2014 .

[33]  I. Bogdanov,et al.  A Methodological Analysis of the Mechanisms Associated to Steam-Solvent Co-injection Processes using Dynamic-Gridding , 2014 .

[34]  J. Sheng,et al.  Evaluation of the EOR potential of gas and water injection in shale oil reservoirs , 2014 .