渤海稠油油藏多元热流体开发全过程参数优化

多元热流体技术是海上稠油高效开发的关键技术,在渤海油田开发中得到了广泛应用,但目前该技术还存在注入参数不合理、转驱时机及井网不确定等问题。为了提高多元热流体技术在油藏开发全过程中的效果,以渤海A稠油油田区块的油藏参数建立数值模型,通过数值模拟方法对多元热流体吞吐阶段主要注入参数、转驱时机及井网、多元热流体驱阶段主要注采参数进行优化研究。结果表明,多元热流体技术在稠油油藏开发过程中,先以吞吐形式进行,当地层压力降至5 MPa左右时再转驱；多元热流体吞吐阶段,随地层压力减小,最佳注水强度先增大后减小,气水比先保持较低水平后大幅增大,气体中CO2比例逐渐减小；多元热流体驱阶段,随含水率上升,最佳注水速度先减小后保持较低水平,最佳气水比的变化规律与注水速度基本相反。

Parameter Optimization for Whole Process of Multi-thermal Fluid Development for Offshore Heavy Oil Reservoir

Multi-thermal fluid technology is a key technology for the efficient development of offshore heavy oil, which has been widely applied in the development of Bohai Oilfield. However, there still exists some problems in the application of multi-thermal fluid technology such as unreasonable injection parameters, uncertain turning timing and well pattern. In order to improve the development performance of multi-thermal fluid technology in the whole development process, a numerical model was established according to the reservoir parameters of the A block in Bohai Oilfield, and the main injection parameters and turning timing and well pattern were optimized. The results show that it is better to turn from multi-thermal fluid huff and puff to multi-thermal fluid flooding when the formation pressure decreases to about 5 MPa. During the multi-thermal fluid huff and puff stage, with the decrease of formation pressure, the optimal water injection intensity first increases then decreases, the gas-water ratio first keeps the low level then increases greatly, and the proportion of CO2 in the gas gradually decreases. During the multi-thermal fluid flooding stage, with the increase of water cut, the optimal water injection rate first decreases then keeps the lower level, and the optimal gas-water ratio has the opposite change law to the water injection rate.