裂缝—孔隙型储层在交变压力条件下的渗透率变化——以四川盆地东部沙坪场石炭系气藏为例  

Permeability changes of fracture-pore type reservoir under the conditions of alternating pressure:Case study of Shapingchang carbonate gas reservoir in eastern Sichuan Basin

作　　者：朱华银 唐立根[1,2] 庞宇来 李隆新[4] 石磊[1,2] 武志德 张敏 殷洪川[3] 罗瑜 ZHU Hua-yin;TANG Li-gen;PANG Yu-lai;LI Long-xin;SHI Lei;WU Zhi-de;ZHANG Min;YIN Hong-chuan;LUO Yu(CNPC Key Laboratory of Oil&Gas Underground Storage Engineering,Langfang 065007,China;PetroChina Exploration&Development Research Institute,Beijing 100083,China;Chongqing Division,PetroChina Southwest Oil&Gasfield Company y Chongqing 400021,China;Exploration and Development Research Institutey PetroChina Southwest Oil&Gasfield Company,Chengdu 610041,China)

机构地区：[1]中国石油天然气集团有限公司油气地下储库工程重点实验室,河北廊坊065007 [2]中国石油勘探开发研究院,北京100083 [3]中国石油西南油气田公司重庆气矿,重庆400021 [4]中国石油西南油气田公司勘探开发研究院,四川成都610051

出　　处：《天然气地球科学》2021年第6期914-922,共9页Natural Gas Geoscience

基　　金：中国石油重大科技专项“地下储气库关键技术研究与应用”(编号:2015E-4002)资助。

摘　　要：四川盆地东部沙坪场石炭系气藏为裂缝—孔隙型碳酸盐岩气藏,储量规模大,储层埋藏深,裂缝发育,非均质性强,具有中低孔中低渗的特征。气藏目前已到开发中后期,为适应我国储气库大规模建设的需要,通过前期库址筛选,认为具有改建储气库的可能,但需要进一步开展评价研究,尤其是储气库交替大吞大吐的生产条件下,储层物性与渗流特征的变化需要加强研究。通过系列实验,结合现场生产测试数据,建立了交变压力下的储层应力敏感性研究方法,分析气藏开发地层压力下降后储层物性变化特征,以及改建储气库后在交变压力下的物性变化规律。结果表明,沙坪场石炭系储层的渗透率与有效压力成幂函数关系,裂缝型储层应力敏感性较强,气藏由原始地层压力约55 MPa下降到目前约10 MPa,3类储层渗透率具有不同程度下降,孔隙型、孔(洞)缝型、裂缝型分别下降了约5%、15%和41%;而作为储气库后假设在30~55 MPa之间运行,则其渗透率变化在3%~28%之间。The carboniferous gas reservoir in Shapingchang is fissure-pore carbonate gas reservoir with large reserves,deep reservoir burial,developed fractures,strong heterogeneity and features of medium and low porosity,medium and low permeability.It is in the middle-late stage of development.In order to meet the needs of large-scale construction of gas storage in China,it is considered possible to rebuild the gas storage by screening and evaluating in the early stage.However,it is necessary to further carry out the preliminary evaluation research,especially under the production condition of gas storage alternately swallowing and spitting.The change of reservoir physical property and seepage characteristics needs to be strengthened.Through a series of experimental studies,combined with the field production test data,this paper established a reservoir stress sensitivity research method under alternating pressure.It analyzed the reservoir physical property change characteristics after the drop of formation pressure in gas reservoir development,as well as the physical property change law under alternating pressure change after the reconstruction of gas storage.The results show that the permeability of Shapingchang Carboniferous reservoir is a power function with effective pressure.The stress sensitivity of fracture reservoir is strong.The gas reservoir has decreased from the original formation pressure of about 55 MPa to the present about 10 MPa.The permeability of the three types of reservoirs has decreased to different degrees.The porosity type,pore(hole)seam type and fracture type decreased by about 5%,15%and 41%respectively.However,if the gas storage is assumed to operate between 30 and 55 MPa,the permeability changes between 3%and 28%.

关 键 词：沙坪场气藏 储气库 储层应力敏感性 交变应力 渗透率 实验 试井测试 

分 类 号：TE122.22[石油与天然气工程—油气勘探]