利用侧钻井技术挖潜苏北老区剩余油研究

Remaining oil tapping by the usage of sidetracked hole technology in old Subei area

苏北老区多为复杂断块油藏,油藏内部低序级断层发育、含油小层多,且具有平面纵向非均质性严重、叠合程度差以及封闭性强等地质特征。由于边底水锥进及注水单向突进等原因,多数区块已进入高含水开发期。在采油井水锥之间、构造高部位或局部高点、沿断层一线附近容易富集剩余油。同时由于井况问题突出,原井网对于油田开发的不适应性逐渐表现出来。开采前期一般靠补充完善井进行调整,开发中后期受投资效益等限制,侧钻井技术利用已有资源,以投资低、钻井周期短等特有优势,形成苏北老区挖掘剩余油的一种重要手段。

As mainly complex fault block reservoir, old Subei area has some geologic features, including low level fault develop- ment, more small oil bearing formations, serious heterogeneity in lateral and vertical directions, low degree of superposition and strong degree of closure. Due to edge and bottom water coning and water injection unidirectional dash, most blocks enter high water cut development period, in addition, remaining oil is easily enriched in intermediate position, high part, local high point and area near fault line of production wells, meanwhile, because of obvious well condition problems, the inadaptability of original well pat- tern gradually appears. In the early stage of production, supplementary improved wells are adopted to adjust the inadaptability, how- ever, in the middle and later development period, due to the limitation of investment benefits, by the adoption of existing resources and through taking advantages of low investment and short drilling cycle, sidetracked hole technology becomes an important mea- sure to tap remaining oil of old Subei area.