濮城油田低渗高压注水油藏转CO2驱技术及应用

濮城油田卫42区块油藏埋藏深,储层物性差,导致该区块注水开发难度大,采出程度低,开发效益差。为此,针对高压低渗注水困难油藏,开展核磁共振实验及长岩心驱替实验,并在实验研究基础上,对卫42区块开展CO_2驱方案设计优化,建立可以模拟人工裂缝的油藏数值模拟模型,进行井网井距论证及参数优化。现场选取6个井组,开展注CO_2驱先导试验,注气压力较注水压力降低了17 MPa,有效补充了地层能量,在水驱基础上可提高采收率15%,取得了良好的增油效果。

Technology and application of CO_2 flooding in low-permeability and high-pressure water injection reservoirs in Pucheng oilfield

The deep burial and poor reservoir physical properties of Wei-42 block in Pucheng oilfield lead to the difficulty of waterflooding development, low recovery degree and poor development benefit. For this reason, nuclear magnetic resonance(NMR) and long core displacement experiments are carried out for high-pressure and low-permeability reservoirs with difficult water injection. On the basis of experimental research, CO_2 displacement scheme design optimization is carried out for Wei-42 block, and the reservoir numerical simulation model which can simulate artificial fracture is established, well spacing demonstration and parameter optimization are carried out. Six wells were selected and pilot test of CO_2 injection was carried out. The injection pressure was 17 MPa lower than that of water injection, which effectively supplemented formation energy and enhanced oil recovery by 15% on the basis of water flooding.