西湖凹陷HY气田储层孔隙结构差异对其渗流特征的影响

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TheInfluence ofDifferencesin Pore Structure of HY Gas Field Reservoir in Xihu Depression on Its Permeability Characteristics

DUAN Dongping1*，U Binbin1， PANG Yu2 ， SHI Qiong1，LI Wenjun1， TANG Hongming³

1.CNOOCChina Limited，ShanghaiBranch，Changning，Shanghai 2ooo51，China 2.ResearchIsiuteoxploatiodelopntouthetOilFeldayetroaduan 3.SchoolofGeoscienceandTechnologyouthwestPetroleumUniversity，hengdu，Sichuan6o5oo，ina

Abstract： Acuratecharacterizationof microscopic pore structure is the keyto evaluating reservoirresources and productivity. Takingthe low-tight permeabilitysandstonereservoirofthe Huagang Formationinthe HYGas Fieldof the Xihu Depression as an example，porestructure parameters are characterized ona ful-scale basis bycombining low-pressure nitrogen adsorption，high-pressuremercuryijection，andnuclear magneticresonance technology.Combined withthesteady-stategaswater relativepermeabilityand movable fluidsaturation experiments，thereservoir sepage mechanismand control factors arecomprehensivelyevaluated.Theresultsshowthat theproportionofdisolved pores inreservoirsamples increases，andthepore size decreases graduallfromtypeItotypeIVreservoirs inthestudyarea.The proportionsofpore throatswithradius greaterthan 1μm are 50.7% 41.3% 25.2% and 5.7% ， respectively. With the deterioration of pore structure quality， the gas-water relative permeability curve in the study area shifts to the right， and the irreducible water saturation ranges from 15% to 55% . The effective permeability of the gas phase ranges from 0.01 to 9.00mD ，and the water saturation in the range of gas-water co-seepage is 6%～65% .When the flowback pressure gradient is 9MPa/m ，theaverage movable fluid saturation of the reservoir exceeds 50% ， and the pore throat connectivity is good. The water film occurs in the pore throat radius μm .Thereservoir seepage capacity is worse were a larger proportion of the water film.The research results have significant guidancefor formulatingeffective development countermeasures and predicting gas well productivity in this area.

Keywords： HuagangFormation;low-tightpermeabilitysandstone;pore structure;seepage mechanism; movable fluid 网络出版地址：http：//link.cnki.net/urlid/51.1718.te.20250508.2001.002

引言

低渗致密砂岩气是非常规天然气的主要类型，在中国油气勘探领域愈发重要，虽然近几十年以来常规天然气仍是天然气供需的主力，但其所占比例逐年下降，低渗致密砂岩气产量逐年增加。（剩余19384字）