特低丰度油层沉积相分布对水平井网开发效果的影响

Effect of sedimentary facies distribution of special low abundance oil layer on horizontal well pattern development

由于特低丰度油层具有厚度超薄的特点,地层的导流即供液能力是决定开发效果的关键因素;而地层导流能力决定于地层物性和砂体厚度,后两者与沉积相展布有直接的关系,因此水平井网布井必须考虑沉积相展布的影响。设计水平井与沉积相带、物源方向的不同位置和方向关系,运用数值模拟方法研究物源方向和相带分布对水平井网开发效果的影响规律,从而选取最佳布井策略。水平井网的水平井段方向应该与沉积物源方向垂直,水平井穿越多种相带时,相带的排列次序对开发效果无明显影响;当水平段落入河间砂坝,并与主河道相邻时,水平井的累产油量高于水平段落入主河道及席状砂的情况。

The special low abundance oil layer is particularly thin, so, the fluid diversion of formation, namely, the feed flowing capacity, is the key factor affecting the development. The feed flowing capacity depends on formation physical properties and sandbody thickness, and these 2 factors are relative to the distribution of sedimentary faeies. So, the effect of sedimentary facies distribution on horizontal well pattern should be considered. Different location and direction relationships between the horizontal well and sedimental3 facies belt and matter sources direction have been designed, and numerical siniulation method has been applied to the research on the effect of matter sources direction and facies belt distribution on horizontal well pattern development to optimize well spacing. The horizontal hole section direction ought to be vertical to the sediments source direction, and when the horizontal well penetrating many facies belts, the distribution sequence of facies belt has no obvious influence on development results. When the horizontal hole section is in inter - river sand bar and is adjacent to the drainage line, the cumulative oil production of horizontal wells is higher than that of the horizontal hole section in the drainage line and in sand sheet.