Importance of Multiple-Contact and Swelling Tests for Huff-n-PuffSimulations: A Montney Shale Example 机翻标题: 暂无翻译,请尝试点击翻译按钮。

SPE Annual Technical Conference and Exhibition: 26-29 October 2020, Virtual
University of CalgaryUniversity of CalgaryOvintiv
Hamidreza Hamdi;Christopher R.Clarkson;Ali Esmail
Accurate assessment of Huff-n-Puff(HnP)performance using compositional reservoir simulation requiresa representative fluid model tuned to several PVT measurements.In unconventional reservoir applications,fluid models are typically constructed using laboratory depletion tests(e.g.CCE and CVD)only.In thiswork,multiple depletion and gas injection tests(e.g.swelling,shrinkage,and multiple-contact tests)areintegrated to construct a common Equation of State(EOS)that is used to evaluate HnP performance fora Montney light oil example.Several sets of depletion and gas injection PVT data were available for this study.However,the injectiontests were conducted using oil samples taken at different production times.Further,different hydrocarboninjection gases were used to perform the experiments.Building a common EOS for this range ofmeasurements,which were conducted on multiple samples,is not a straightforward task.Therefore,aworkflow,and several computer programs,are developed to simulate all the PVT tests simultaneously and toconduct the regression process.The resulting EOS is then used to construct a representative compositionalsimulation model.The model is calibrated through history-matching and employed to design an optimalHnP process for the studied Montney well.The results are then compared with a case where no injectiontests were used to develop the fluid model.The results indicate that it is particularly challenging for the regression process to maintain a balancebetween the quality of the match for the depletion and the injection tests.This process required some uniqueglobal optimization methods to build a reliable EOS that matched all the measured data.For this study,the importance of the injection PVT tests is mainly reflected in tuning the interfacialtension,and secondarily the viscosity and phase density values.However,in this case study,it appears thatthe importance of the injection tests for tuning the EOS is marginal.In other words,depletion tests weresufficient to calibrate an EOS that resulted in an acceptable match to many measured data points obtainedfrom multi-contact and swelling tests.This finding is mainly related to the fact that all the injected gasesare hydrocarbon gases with a composition consistent with the solution gas in the oil samples.Therefore,the PVT model could also be used for injection simulations,even though the EOS was calibrated to the depletion tests only.However,it is expected that this is not the case for other non-hydrocarbon gas injectiontests(e.g.using CO2 or N2)where the depletion tests cannot easily constrain the properties of the injectantsduring the depletion process.The constructed PVT models are used as input to dual-porosity dual-permeability(DP-DK)models,which are calibrated using multi-phase production data.The results further indicate that the two EOSs couldpredict an optimal HnP process with a minimal recovery difference.A new fluid modelling workflow is introduced for the first time to evaluate the importance of variousgas injection PVT experiments on HnP performance prediction.This new method is tested against afield example with several measurements from a multi-fractured horizontal well(MFHW)in the MontneyFormation in Canada.