港东油田一区一断块高含水后期开发的几点做法

Some works done for the efficient development of Gangdong No.1 faultblock at its later stage of high water cut.

大港油田港东一区一断块为港东油田的主力断块 ,目前已进入特高含水开发阶段。受发育后期曲流河沉积的影响 ,地层非均质严重 ,加上长期注水开发 ,使断块进入特高含水开发阶段后 ,油层水淹加剧 ,剩余油分散 ,挖潜难度加大。为此 ,1991年对注水最完善的明二单元率先进行油藏描述和剩余油分布规律研究。在此基础上 ,针对开发中存在的实际问题 ,进行了一系列挖潜工作。主要包括 :①实施层系互换 ,完善注采井网 ;②钻加密调整井 ,挖掘死油区 ,提高断层附近及构造高部位剩余油动用程度 ;③实施精细注水 ,充分挖掘低渗透率控制的剩余油。主要从 3个方面整体实施 ,一是增加注水井点 ,缩小注水半径 ,改变液流方向 ,提高注水扫油面积 ;二是加强高含水层的专项治理 ,重点突出注水井的调剖工作 ;三是脉冲注水 ,通过周期性地强弱交替注水 。

Gangdong No.1 f ault block in Dagang oil field is one of the main fault blocks and has been ent ered its stage of high water cut. Eff ected by later stage of meandering river deposition, reservoir is highly heterog eneous. Due to long term water injection, this fault block has entered into its extra high water cut development stage. The reservoir is seriously flooded, th e remaining oil is highly scattered and the potential can hardly be tapped. Unit Ming No.2 in this block which is water injected by a fairly perfect injection p attern is studied by reservoir description for determining the distribution of r emaining oil. A series of works on potential tapping is carried out: (1) exchang ing injection and production layer group, and perfecting injection production w ell pattern; (2) drilling infill wells to penetrate the by passed oil area to e nhanced the degree of extraction of the remaining oil at structurally high posit ion and near the fault; (3) carrying out sophisticated separate layer water inj ection to fully develop the remaining oil in the low permeability part. This can be done further by increasing the number of injection wells to reduce the injec tion radius, to change the direction of water flow and to increase the water swe pt area; Enhancing the development efficiency of high water cut layers through profile modification and water injectors; and carrying out pulse water injection to improve the water displacement efficiency by alternating strong and weak wat er injection cyclically.