摘要: |
特低渗油藏的生产井初始含水率要比中髙渗油藏的高,而且生产井开井生产后含水率有一段时间的下降。对 流体流动的微观机理进行了分析。结果表明,在特低渗油藏,钻井和压裂过程造成的水锁玫应使地层原油难以流 动;贾敏效应的存在阻塞了油流的通道;地层微裂缝的开启与闭合、启动压力梯度的存在导致生产井初始含水率较 髙;岩石物性特征决定了油藏的初始含水饱和度高,进而使初始含水率比较卨。 |
关键词: 特低渗油藏 微裂缝 初始含水率 启动压力梯度 水锁效应 贾敏效应 |
DOI: |
分类号: |
基金项目:中石化集团公司科技攻关项目(P050203 ) |
|
Microscopic seepage mechanism of initial high water cut of production wells in ultra-low permeability reservoir |
GU Jian-wei1,GUO Zhi-hua2,ZHAO Yan1
|
(1. College of Petroleum Engineering in China Universiiy of Petroleum, Dongying 25706,Shandong Province, China;2. Xianh^ Oil Production Plant of Shengli Oilfield Branch Company, SINOPEC, Dongying 257067,Shandong Province, China)
|
Abstract: |
The initial water cut of production wells in ultra-low permeability reservoirs is higher than that of in high permeability reseivolre, and the dropping trend of water cut will last for days in developing period. The analysis reaults of microscopic seepage mechanism show that oii flowes with drfficalty because of the water lock effect resulted from drilling; and iraciunng. Jamin effect, the open and close a£ microfractiira, starting pressure gradient in reservoir result in high initial water cut. Because of thin throat of rocka, the initial water saluration is high, which results in the high initial water cut of production wells. |
Key words: ultra-low permeability reservoir microfracture initial water cut ^rarting pressure gradient water lock effect Jamin effect |