摘要
L礁灰岩油藏发育天然裂缝且拥有中高渗基质,强底水驱开发后期油水渗流及分布规律复杂,挖潜效果不理想。本文通过岩心薄片微观水驱油实验和全直径岩心驱替实验综合研究,明确了强水驱开采“裂缝快速水窜,基质渗流受阻,基质原油在渗吸作用下缓慢流入裂缝,以水包油形式被驱出”的渗流规律。高含水老井间的加密井实钻显示储层无水淹迹象但开井即高含水,证实了水驱平面波及范围小,高含水期“裂缝网状水淹,基质动用程度低,井间富含油”。进而提出了井间加密辅助裂缝充填控水的挖潜策略,通过微粒充填裂缝以降低导流能力,延缓水窜。矿场已实施井的控水增油效果显著,单井含水率下降34.6%~76.3%,预测净增技术可采储量6.1×104m3~15.5×104m3。
L oilfield is a reef limestone reservoir with numerous natural fracture and medium to high permeability matrix.Oil-water seepage and distribution become complicated during mid-late period of strong bottom water driving,getting poor performance of remaining oil development.This paper gets the oil-water seepage mechanism from experiments of micro core flakes and diameter core displacement.That is,water channeling rapidly through natural fracture,resulting in low oil mobility in matrix.Then,oil in matrix can only flow into fracture by imbibition and is produced with water.Infill wells is drilling between older wells high water cut.Results show the formation has no sign of water flooding,while opening up with high initial water cut.These indicate that drainage radius is smaller.During high water cut development period,fracture network is flooded by water.Oil recovery factor in matrix is lower,resulting in rich remaining oil among older wells.Then the development strategy is proposed,infill drilling between older wells with fracture filling water control.Filling fracture pores by particles around infill well can reduce fracture flow capacity,delaying water channeling.Application in several wells are successful,resulting in 34.6%~76.3%of water cut decrease and 6.1×104m3~15.5×104m3 of technically recoverable reserves increase per well.
作者
张晓林
王亚会
徐伟
汤小龙
ZHANG Xiaolin;WANG Yahui;XU Wei;TANG Xiaolong(CNOOC China Limited,Shenzhen Branch,Shenzhen Guangdong 518054,China)
出处
《石油化工应用》
CAS
2021年第11期15-20,共6页
Petrochemical Industry Application
基金
中国海油重大科技专项课题四:礁灰岩油田高效开发技术研究,项目编号:CNOOC-KJ 135 ZDXM 37 SZ 04 SZ。
关键词
礁灰岩
天然裂缝
强水驱
渗吸
控水
reef limestone
natural fracture
strong water driving
imbibition
water control
