用自然电位解释孔隙压力

Application of Spontaneous Potential in Interpretation of Pore Pressure

过去常采用声速法估算储集层孔隙压力,对于目前层间压力变化极大的大庆油田,声速法遇到了困难。经长期注水开发的砂岩储集层,自然电位的变化主要由过滤电位的变化所引起,而过滤电位与压差密切相关,由此引出了应用自然电位解释孔隙压力方法。以大庆油田砂岩储集层为例,依据自然电位测井原理和毛管流动电位理论提出了适用于油田开发过程中解释砂岩孔隙压力的自然电位法,提高了压力解释精度,可节约大量的测试费用,为油田开发过程中孔隙压力解释提供了新的思路。

T he sonic velocity approach used to be applied for estimation of reservoir pore pre ssure.However,it doesn't operate to Daqing oil-field with diversified current interlayer pressures.Following long-term waterflooding,the sandstone reserv oir has variable spontaneous poten-tial(SP)resulted from variable electrofilt ration potential which is closed with the pressure drawdown.The SP approach is introduced from it.Taking the sandstone reservoir in Daqing oilfield as an exam ple,this paper presents a SP approach applicable to interpret the sand pore pre s-sure variations during the field development,based on SP log principle and c apillary flow potential theory.It is indicated that as a new thought,using thi s approach may improve the accuracy in the pressure interpretation,hence save a great amount of testing fees.