复杂断块油藏剩余油分布及配套挖潜对策

Remainined oil distribution in complicated faulted blocks and its accessory potential exploitation measures

复杂断块油藏开发后期剩余油分散而难以识别,且其分布受多种因素的控制。在大港油区的港东开发区,根据以纵向118个时间地层单元为对象的精细油藏描述,提出3类剩余油潜力:①已动用油层,即断层与微构造控制、注采井冈不完善、层间非均质性、平面低渗透相带、层内渗流屏障、注采滞留区、边底水锥进等因素形成的剩余油;②新层,即以往未发现的低电阻油层和新发现油砂体;③滚动扩边。在潜力认识的基础上,以单砂体或流动单元为挖潜调整对象,在潜力富集区钻新井、更新井,改变非主力层的驱动方式,重组层系、井网,改变液流方向和间歇注水,并对潜力区配套实施补层、提液、压裂防砂、重复射孔、深度调剂等措施。港东开发区复杂断块油藏实施配套挖潜措施后,提高了高含水期的开发效益与水平。

Within the Gangdong development area of Dagang Oilfield, three kind potential areas of remaining oil are put forward by means of reservoir fine description which takes 118 time-stratigraphic cells as study targets. Producing oil formation is the first kind, in which the remained oil are dominated by fault and micro-structure, imperfect injection and production pattern, interval heterogeneity, low permeable zone on plane, internal seepage barriers, the stagnant area of injection and production, bottom water coning and so on. The second is new-strata, involving the low-resistively oil formation not being found in the past and the oil sand being found freshly. The third is progressive development area. Taking single sand bodies and flowing cells as the potential-finding and adjusting targets, the new and renewal wells are drilled in potential enriched areas, driving types of non-dominating oil formation are changed, layer series and well pattern are regrouped, the fluid direction is changed and cycle injection is adopted, and at the same time, to potential areas, new layers are perforated, liquid productions are increased, fracturing and sand prevention, re-perforation, and deeply profile controlling technologies and so on are applied. After the accessory potential exploitation measures of complicated block reservoir of Gangdong development area are put into practice, both the development benefits and levels of high water-cut are improved.