驱泄复合开采技术在风城超稠油油藏中的应用

Application of Vertical-Horizontal Steam Drive Process to Fengcheng Extra-Heavy Oil Reservoir, Junggar Basin

超稠油油藏在蒸汽驱过程中,主要受蒸汽驱动力和重力的作用,表现为蒸汽驱油和重力泄油两种驱替方式,即驱泄复合开采。应用解析和数值模拟方法,描述了驱泄复合开采机理,明确了注汽方式、注采参数和调控政策。研究表明,风城油田重32井区齐古组超稠油油藏采用直井注汽-水平井采油组合方式驱泄复合开采技术的合理操作条件是:直井采用轮换注汽,注汽速度70 t/d,井底蒸汽干度大于70%,操作压力为2.5 MPa,采注比为1.2;主要调控技术是注汽点优化、饱和温差调控、注采平衡和工作制度优化。预计采收率可达50%.

An extra-heavy oil reservoir developed by horizontal well steam drive process appears two states of steam flooding and gravity drainage in process of driving force and gravity, it is known as vertical well steam injection-horizontal well production steam drive （VHSD） process. This paper describes this mechanism, steam flooding mode, injection-production parameters and adjustment and control policy hy means of analytical and numerical simulation methods. The study shows that in the area of Well Zhong-32 in Fengcheng oilfield, the suit- able operation conditions for the Qigu extra-heavy oil reservoir developed by VHSD process are that vertical well uses rotating steam injection with steam injection rate of 70 t/d, steam quality at the bottom of higher than 70%, operation pressure of 2.5 MPa, and production/injection ratio of 1.2. The main control technique is the optimization of steam injection spot, sub-cool regulation, injection-production balance and working system optimization. The expected recovery efficiency can reach 50%.