Abstract:

Complex geological environment, such as high temperature, pressure and salinity, is involved in the recovery of deep oil and gas resources. It is well known that there exists high concentration of brine in natural reservoirs and salts deposit during the recovery of oil and brine, when temperature, pressure and the amount of dissolved gases vary. Reservoir damage or well-bore jam is caused by the deposition of salts in the reservoir and well-bore. These are the major factors reducing oil and gas recovery. Currently, phase equilibrium model for describing the deposition behavior of salts from high pressure and salinity reservoir fluids is under development. In this paper, the progress in improving the mixing rule of equation of state parameters by combining a group contribution activity model for electrolyte solutions is reported.

Key words: oil and gas, salt, deposition, phase equilibrium, model

摘要：

深层油气资源开发面临高温、高压和高矿化度等复杂地质环境。地层中自然存在高浓度的盐水,在油水被采出的过程中,随着温度、压力和油水中溶解气体量的变化,盐类在储层中或在井筒中的沉淀所造成的储层伤害或井筒堵塞等问题是导致油气采收率降低的重要因素。目前,能描述高压高矿化度油气藏流体盐的沉淀问题的相平衡模型尚处于开发之中,采用电解质溶液基团贡献的活度因子模型来改进状态方程的混合规则是解决这一问题的途径之一。

关键词: 油气, 盐, 沉淀, 相平衡, 模型