致密油藏CO_2驱综合效益评价

致密油藏储量大,开发成本高,实现经济开发至关重要。以C油田致密油藏典型区块为例,采用直井—水平井联合布井方式,通过数值模拟,讨论了5种不同渗透率级别、8种排距下CO2驱的开发效果,结合经济评价指标分析不同油价下CO2驱的经济效益。研究表明,当前油价下,渗透率在0.1×10-3~1×10-3μm2时,建议C油田致密油藏典型区块采用注CO2开发方式;缩小排距,采出程度提高,内部收益率降低,建议根据C油田开发方针和原则选择合适的排距;增加生产年限,累计采出程度提高,经济效益呈现降低趋势,建议C油田根据自身情况需要选择合理的生产年限。

Comprehensive benefits evaluation of CO2 displacement in tight oil reservoirs exploitation

Tight oil reservoir has big geological reserves but its exploitation is of high cost, so how to achieve economic exploitation has gradually been received attention. In this paper, we take the C oil field as an example, and adopt the combination well spacing of vertical and horizontal wells to establish a geologic model, then discuss the exploitation effect of CO₂ displacement under five different permeability levels and eight different row spacing distributions. Finally, we deeply analyze the economic benefit of CO₂ displacement under different oil prices with the help of economic evaluation criteria. Through the above research, we obtain the following conclusions: When the permeability is between 0.1×10^-3 μm² and 1×10^-3 μm², the C oil company should choose the CO₂ displacement exploitation rather than waterflooding under the current oil price; although decreasing the row spacing will enhance oil recovery, it will decrease the economic benefit, so the C oil company should adopt the appropriate row spacing according to their own current situation; prolonging the productive life will increase the production rate of recovery, but that is no good to the economic benefit, so the C oil company should choose the appropriate productive life by self-condition.