大古67块特低渗透油藏开发探索与实践

Exploration and practice of ultra-low permeability reservoir development of Dagu 67 block

大王庄油田大古67块是一个深层、特低渗透、断块油藏,平均空气渗透率9.6×10^(-3)μm^2,主要含油层系是二叠系石盒子组,从试油至今经历了天然能量开采、注水开发稳产、加密调整增产三个开发阶段。开发上具有油井投产初期产能差异大、天然能量不足产量递减快、储层物性差注水井吸水能力差等特点。经过多年的开发探索总结出应用井网井距优化、强化有效注水、压裂油层改造以及油层保护等开发技术,可以有效提高特低渗透油藏开发效果。该块目前平均单井日产油量5.3t,综合含水28.1%,采出程度8.74%,采油速度1.27%。

Dagu 67 block of Dawangzhuang oilfield is a fault block reservoir with deep depth and ultra - low permeability of 9.6×10^(-3)μm^2,and the main oil-bearing series are Shihezi formation of Permian.Starting from formation testing,the block has experienced three development stages;natural recovery phase,water flooding phase and infilling adjustment, with the characteristics of big difference of initial productivity, quick production decline,poor physucal properties and poor capacity of water absorption.Therefore,through many years of development exploration,the development techniques such as optimized well spacing and well pattern,intensify water flooding,fracturing reform,and reservoir protection, which can effectively enhance the development effect of the ultra-low permeability reservoir.At present,the daily oil production of single well is 5.3 t,with water cut of 28.1%,recovery of 8.74%and the oil producing rate of 1. 27%.