Abstract: Shenbei buried hill high pour-point oil reservoir of Liaohe Oilfield is hard granite formation with a poor physical property. The single-well production of vertical well and horizontal well is relatively low while the development cost is high, because fractures developed at random. To lower comprehensive development cost and improve single-well drainage area and fracture-drilling rate, the multilateral horizontal well technology was used for development. As a result, oil production was raised thanks to remarkable results. However, there is a series of stern challenges facing field application. For example, efficiency ofcasingsidetracking waslow inthe highly-abrasive hard granite formation. It is difficultfor lateral drilling ofa fishbonewell.The branch hole of fishbone well is simple in completion, short in service life and poor in water and sand control. Reservoir is easily damaged.As for those technological issues, the efforts were made to study the technology of casing sidetracking in hard formation and lateral drilling process of compound fishbone well and combine under-balance technology with fishbone well drilling and completion technology. Progress has been made in effective discovery and protection of oil and gas reservoirs to maximize footing of reservoir. Perfection of branch horizontal well process promotes large-scale deployment of branch horizontal wells ona buried hillblock.This technology is of great significance to reduce development cost per unitfor buried hillfractured high pour-point oilreservoirs.

Key words: multi-lateral horizontal well; buried hilloilreservoir; casing sidetracking, ;fishbone lateralwell

摘要： 辽河油田沈北潜山高凝油油藏储层为花岗岩硬地层,物性差,裂隙发育随机性大,直井、水平井单井产量都比较低,而且开发成本高。为降低综合开发成本,增加单井的泄油面积和裂隙钻遇率,尝试利用分支水平井技术开发,效果明显,产量提高。然而现场应用中遇到一系列严峻的挑战,例如,高研磨性花岗岩硬地层套管开窗效率低,鱼骨分支侧钻难;鱼骨分支井眼完井方式简单,寿命短,控水防砂效果差;储层易伤害等等。针对以上技术问题,开展了硬地层套管开窗技术及复合鱼骨井眼侧钻工艺研究,并将欠平衡技术与鱼骨井钻完井技术相结合,取得了突出进展,有效发现并保护了油气藏,实现了储层的最大化进尺。分支水平井工艺的完善推动了潜山区块的规模化分支水平井布井开发。这项技术对于降低潜山裂隙高凝油油藏的吨油开发成本具有重要意义。

关键词: 分支水平井, 潜山油藏, 套管开窗, 鱼骨分支井