福山凹陷低渗透油藏启动压力梯度实验研究  

Experimental study on start-up pressure gradient of low permeability reservoirs in Fushan sag

作　　者：贾然 Jia Ran

机构地区：[1]中国石油长城钻探工程有限公司录井公司

出　　处：《录井工程》2018年第4期20-23,99,共5页Mud Logging Engineering

摘　　要：常规油藏开采日渐匮乏,而低渗透油藏储量高,其开发成为当前研究热点。鉴于室内启动压力梯度实验结果可反映储集层的渗流规律,为低渗透油藏开发方案设计、井距选取及储集层动用情况提供数据支撑,选取福山凹陷低渗透油藏天然岩心,在参考前人研究成果的基础上,总结出一种以气体作为输出动力,通过定值器精密调节输出压力的实验方法。该实验研究表明:福山凹陷低渗透油藏启动压力梯度与气体渗透率有较好的乘幂负相关关系,通过实验数据拟合求得的最小启动压力梯度贴近生产实际;现阶段注采压差小、注采井接近极限井距是该区块注水难、采收率降低的主要原因。最终研究结果可有效验证研究区采油井改为注水井效果的优劣,为下一步选取注水井改造提供理论图板。With the shortage of conventional reservoir exploitation and the high reserves of low permeability reservoir,its development is the current research hot spot.In view of the fact that the results of laboratory start-up pressure gradient test reflect the seepage law of reservoir,it provides data support for the design of low permeability reservoir development plan,well spacing selection and the drainage volume of reservoir.Based on selecting natural core of low permeability reservoirs in Fushan sag,referring to the previous research results,and using air as the output power,an experimental method of minutely adjusting the output pressure with set point device was summarized.The experimental results showed that start-up pressure gradient of low permeability reservoirs in Fushan sag has a good power negative correlation with gas permeability.The minimum start-up pressure gradient obtained by fitting the experimental data is close to the production practice.At present,small injection-production pressure difference and near critical well spacing between injection wells and production wells are the main reasons for the difficulty of waterflooding and the decrease of recovery efficiency in this block.The results of the final study can effectively verify the effect of changing production wells into water injection wells in the study area,and provide a theoretical chart for next step to select water injection wells for modification.

关 键 词：福山凹陷 低渗透油藏 启动压力梯度 气体渗透率 极限注采井距 

分 类 号：TE132.1[石油与天然气工程—油气勘探]