调驱技术是低渗透油藏稳油控水的重要手段

Profile Control and Dis-placement Method as an Important Means for Stable Oil Production by Water-Cut Control in Low Permeability Reservoir.

彩南西山窑组油藏微裂缝发育、储集层非均质性强,是典型的低一特低渗透油气藏。经过几年高速开发之后,因水窜、水淹而使油藏含水上升快、产量递减大、地层压力场分布复杂。对此,在深入进行油藏研究,认清砂层在纵向、横向上的发育程度、注采连通程度、储集层沉积微相、岩石物理相、储集层裂缝相、流体流动单元等油藏特征的基础上,对注水井进行普通调剖、深度调剖、“2+3”调驱等措施,使油层动用程度由68%提高至95%,并且在横向上起到了深部液流转向的作用,较大幅度地提高了水驱波及体积和洗油效率,对整个油藏的稳油控水起了重要作用,而且投入产出比在以上,经济效益显著。

Xishanyao reservoir in Cainan oilfield is a typical low-extra low permeability oil pool with well developed micro-fracture and serious heterogeneity of reservoir.Following the several-year high level of production,it has appeared in quickly rising water cut,high pro-duction decline and complicated distribution of formation pressure field due to water breakthrough and watered out.Hence,a series of mea-sures have been taken such as conventional and depth profile controls in water injection wells and'secondary plus tertiary recovery tech-nologies',based on in-depth reservoir studies in order to make sure development of pay zone in vertical and horizontal directions,connection between injection and production wells,reservoir depositional microfacies,petrophysical facies,fractural facies and fluid flow behavior.The results have shown that producing level of pay zone increases from68%to95%,enabling deep flow to be displaced transversely,and improv-ing water flooding swept volume and displacement efficiency.Each injection well is stimulated,and followed by two production wells being responsible in average.Water cut in the stimulated well group decreases from4.5%to2.9%,with production decline slowing down from20%to10%,along with input-output ratio over1:3.5.These profile control measures have played important roles in stable oil production by water-cut control for the whole reservoir,and offered significant economic efficiency.