气顶边水油藏油气协同开发下流体界面运移特征

气顶边水油藏的开发，存在明显的油气水互侵现象，导致产量快速递减，开发难度增大。为了防止生产井过早停产，需明确流体界面运移特征，制定油气协同开发生产制度。本文通过油藏数值模拟方法，建立了月东油田气顶边水油藏实际模型与机理模型，根据气顶与边水作用能量强弱，将油气协同开发区域划分为边水控制区、气顶控制区和气顶边水联合控制区三类进行研究，综合评估气窜、水淹、油侵风险，明确油气、油水界面运移特征并形成运移速度图版。结果表明：随着开发的进行，气顶膨胀导致油气界面从油藏顶部向油井方向运移，边水侵入导致油水界面从油藏底部向油井与气井方向运移，油井存在气窜与水淹的风险，气井存在水淹与油侵的风险，剩余油主要分布在气顶下部和井间高部位，确定月东油田气顶边水油藏合理采气速度为6%~8%。本文基于实际与理论研究形成的成果认识，为气顶边水油藏油气协同高效开发提供理论指导。

Fluid interface movement characteristics of oil reservoir with gas cap and edge water during the process of oil and gas concurrent production

In the production of gas cap edge water reservoirs, a phenomenon of mutual invasion by oil, gas, and water is observed, which leads to rapid production decline and increased development difficulty. In order to prevent the premature shutdown of production wells, it is necessary to clarify the characteristics of fluid interface migration and formulate a production system for the concurrent production of oil and gas. In this paper, the actual model and mechanism model of the gas cap edge water reservoir in Yue Dong Oilfield were established using reservoir numerical simulation methods. According to the energy intensity of gas cap and edge water, the oil and gas concurrent production area was divided into three types: edge water control area, gas cap control area and gas cap edge water joint control area. The risk of gas channeling, water flooding and oil invasion was comprehensively evaluated, and the migration characteristics of oil-gas and oil-water interface was defined and the migration velocity chart was formed. The results show that with the production, the gas cap expansion causes the oil-gas interface to migrate from the top of the reservoir to the oil well, while the edge water intrusion causes the oil-water interface to migrate from the bottom of the reservoir to the oil well and gas well. The oil well has the risk of gas channeling and water flooding, and the gas well has the risk of water flooding and oil invasion. The remaining oil is mainly distributed in the lower part of the gas cap and the high part between the wells. It is determined that the reasonable gas production rate in the gas cap and edge water reservoir of Yue Dong Oilfield is 6% ~ 8%. Based on the results of practical and theoretical research, this paper provides theoretical guidance for the concurrent and efficient production of oil and gas in gas cap edge water reservoir.