玛湖凹陷致密砾岩油藏CO_(2)异步吞吐提高采收率  

Enhancing Oil Recovery of Tight Conglomerate Reservoirs by Asynchronous CO_(2)Huff and Puff in Mahu Sag

作　　者：邓振龙 王鑫[1] 谭龙[1] 张记刚[1] 陈超[1] 宋平[1] DENG Zhenlong;WANG Xin;TAN Long;ZHANG Jigang;CHEN Chao;SONG Ping(Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 834000,China)

机构地区：[1]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000

出　　处：《新疆石油地质》2022年第2期200-205,共6页Xinjiang Petroleum Geology

基　　金：国家科技重大专项(2017ZX05070)。

摘　　要：CO_(2)具有增能和降黏的特性,CO_(2)异步吞吐是提高致密油藏采收率的有效途径之一,通过注气井组“注—采—焖”相互配合,可提高井间储量动用程度,有望成为准噶尔盆地玛湖凹陷致密砾岩油藏提高采收率的接替技术。综合考虑地层压力、饱和压力及最小混相压力,设计双岩心并联的CO_(2)异步吞吐实验,以明确储集层物性、注采压差和吞吐时机对开发效果的影响。结果表明,经CO_(2)异步吞吐开发后的原油采收率约为衰竭式开发的3~5倍,提升效果显著;储集层物性越好,渗流阻力越小,越有利于CO_(2)异步吞吐提高采收率;注采压差越大,井间压力振荡效果越显著,采出原油越多;注气压力大于混相压力时,有利于发挥CO_(2)超临界性质,提高采收率;在地层压力高于混相压力的前提下,CO_(2)异步吞吐时应尽量提高注气井压力并降低邻井压力,增大注采系统压差,从而扩大波及体积,提高井间储量动用程度。CO_(2) can increase formation energy and reduce oil viscosity.Asynchronous CO_(2) huff and puff is becoming one of the effectivemethods for improving the recovery of tight oil reservoirs.The interaction among injection,production and soaking processes can signifi-cantly increase inter-well reserves producing degree,and this technology is expected to become an option for enhancing the oil recovery ofthe Mahu tight conglomerate reservoirs in the Junggar basin.According to the formation pressure,saturation pressure and minimum misci-ble pressure,an asynchronous CO_(2) huff and puff experiment with two cores in parallel was designed for clarifying the influence of reservoirphysical properties,injection-production pressure difference and huff-puff timing on development effect.The results show that the crude oilrecovery after asynchronous CO_(2) huff and puff is about 3-5 times higher than that of the depletion development;the better the physicalproperties of the reservoir,the smaller the flow resistance,and the more favorable for asynchronous CO_(2) huff and puff to improve oil recov-ery;the greater the injection-production pressure difference,the more significant the inter-well pressure change,and the more crude oil isproduced;when the gas injection pressure is greater than the miscible pressure,it is beneficial for supercritical CO_(2)to play the role and toimprove the recovery;when the formation pressure is higher than the miscible pressure,it is necessary to increase the pressure of the gas in-jection well and reduce the pressure of the adjacent production well through asynchronous CO_(2)huff and puff to increase the pressure differ-ence of the injection-production system,expand the swept volume,and improve the inter-well reserves producing degree.

关 键 词：准噶尔盆地 玛湖凹陷 CO_(2) 异步吞吐 提高采收率 储集层物性 注采压差 吞吐时机 混相压力 

分 类 号：TE357[石油与天然气工程—油气田开发工程]