强水敏感性稠油油藏黏土热膨胀性特征研究——以金家油田沙一段为例

金家油田沙一段稠油油藏储层黏土含量高且具膨胀性,导致储层强水敏性,制约油藏热采开发,为此开展了不同温度条件下黏土膨胀性研究。测试实验表明,其黏土矿物类型主要为钙基蒙脱石,低温(45℃地层温度)条件下测试膨胀率平均为26.3%,储层具强水敏性。差热和热重、高压釜高温实验后样品晶间距测试结果表明,在100℃以上的高温条件下,蒙脱石脱水,晶间距变小,膨胀性减弱,水敏性变弱;当温度达到300℃时,蒙脱石晶间距与标准晶间距相近,膨胀性基本消失。

Clay thermal expansion characteristics research on heavy oil reservoirs with strong water sensitivity

The clay content in Sha-1 member heavy oil reservoirs of Jinjia oilfield is high and has the swelling characteristic,which leads to the reservoir of strong water sensitivity,and restrict thermal recovery of the reservoir development.Therefore the research on the clay swelling under different temperature conditions has been carried out.Test results show that the main clay minerals content types are calcium montmorillonite.Under the condition of low temperature,namely formation temperature(45 ℃)test,the average inflation rate is 26.3%,and the reservoir is of strong water sensitivity.After poor heat and thermogravimetric(tg),high temperature autoclave experiment sample wafer spacing test results show that under the condition of the high temperature of 100℃above,the montmorillonite is dehydrated,the crystal spacing decreases,the dilatability is abate,and the water sensitivity is weak.When the temperature reached300 ℃,the montmorillonite crystal spacing is similar to standard crystal spacing,and the swelling disappeared basically.