盐水钻井液侵入地层电阻率校正方法探讨——以埕岛油田馆上段为例

Research and Practice of the Resistivity Correction in Saline Mud Invading Formation:A Case Study of Upper Ng Member in Chengdao Oilfield

埕岛油田馆上段油藏为特高渗、高饱和、岩性构造层状油藏,馆上段储层在油田范围内迭合连片分布,具有埋藏浅、横向变化大、单层厚度小、局部油水关系复杂的特点。埕岛油田在钻井过程中均采用盐水钻井液,对电阻率测井的影响很大,从而影响到储层饱和度参数的正确求取。文中分析了盐水钻井液侵入的影响,进而探讨了电阻率校正方法,应用该项成果,对埕岛油田馆上段进行原始含油饱和度解释和储量计算均取得了较好的效果。

Chengdao oilfield is the first large oilfield which put into production in the extremely shallow water areas in China. Upper Ng member is a lithologic-structural reservoir with the superhigh permeability and the high saturation. Upper Ng reservoir is distributed overlappedly and linkedly in the oilfield, characterized by shallow burial, laterally large variation, thin single bed and complicated local oil-water relation. Generally Chengdao oilfield uses brine water mud during drilling. It has a strong impact on resistivity log, and therefore affects the correct solution to the formation saturation. This paper analyzes the impact induced by the brine water mud, and also discusses the resistivity correction. This result has a significant effect on the interpretation of original oil saturation and reserves calculation of Upper Ng member in Chengdao oilfield.