致密油藏分段压裂水平井注二氧化碳蓄能吞吐方式

随着油田勘探开发程度不断加深，水平井初期产油量低且递减快、地层能量补充不足等问题严重的影响了油田的后续开发。本文通过油藏数值模拟技术，建立概念模型和实际模型，对致密油藏水平井注二氧化碳展开针对性研究，优化能量补充方式，选择合理的生产参数，明确致密油层水平井开发技术对策。结果表明，相同储层条件下，平注平采较直注平采的开发方式可以有效补充地层能量，而二氧化碳吞吐开发方式更合适在渗透率在0.2~0.3mD以下的储层。就研究区块而言，优选其开发方式适合于注二氧化碳吞吐，同时，相较于每吞吐轮次等量注入二氧化碳的方案，逐步提高每吞吐轮次的二氧化碳注入量的方案可以更为有效补充地层能量，使每个吞吐周期产出更多的油，随着吞吐周期的增加，开发效果愈加明显。

A new method of horizontal wells using carbon dioxide huff and puff in tight oil reservoirs

With the deepening of oil field exploration, the problems such as low initial oil production and rapid decline of horizontal Wells and insufficient formation energy supplement have seriously affected the subsequent development of oil fields. The purpose of this paper was to study the effect about injecting carbon dioxide into the tight oil reservoir through the horizontal well, optimize energy supplementation mode, select the reasonable production parameters, and clarify technical countermeasures for the horizontal Wells in tight oil reservoirs, by using numerical simulation to establish conceptual model and practical model. The results show that, at the same reservoir conditions, the development method of horizontal injection and horizontal production can effectively supplement the formation energy compared with that of vertical injection and horizontal production, while the development method of carbon dioxide huff and puff is more suitable for reservoirs that the permeability is below 0.2~0.3mD. In terms of the research block, the preferred development method is carbon dioxide huff and puff. At the same time, compared with the solution which injects the same CO2 injection throughput in per rounds, the scheme which gradually improves the CO2 injection throughput in per rounds can more effectively complement formation energy, produce more oil in each stimulation cycle. As the throughput rounds increasing, the development effect becomes more and more obvious.