海上稠油油藏多元热流体吞吐后转火驱开发研究

Conversion from Multi-Component Thermal Fluid Flooding to Fire-Flooding in Offshore Heavy Oil Reservoir

针对NB35-2油田多元热流体吞吐部分井日产油量降低、回采水率及回采气率升高、井底流压较低的现象,从生产井生产特征出发,将低效井作为转火驱开发研究对象,分析低效原因。利用油藏数值模拟方法,建立考虑多组分转化关系的火驱数学模型,充分利用现有井网条件,以提高火驱单井产能及累计产油量为出发点,优选适合海上稠油火驱的井网类型及驱替模式,论证大井距火驱开发的可行性,并对注采参数进行优化。结果表明,3口不同类型低效井转驱后累计增油13.1×10^4m^3,且边部储量得到有效动用,边部转驱单井累计产油达到12.4×10^4m^3,开发具有一定经济性,满足海上稠油热采少井、高产开发要求。研究结果可对海上稠油油藏开发方式转换提供借鉴意义。

Some production wells in the NB35-2 Oilfield with multi-component thermal fluid flooding are characterized by relatively low daily oil production rate,increasing water recovery factor and gas recover factor,relatively low bottom-hole flowing pressure,etc.The low-efficiency wells were converted to fire-flooding to analyze the low-efficiency factor s by considering the production performances.Reservoir numerical simulation was used to establish a fire-flooding numerical mode by considering multi-component transformation.The present well network was fully used to enhance single-well productivity and cumulative oil production.The well network and displacement mode for the fire-flooding offshore heavy oil reservoir were optimized to demonstrate the feasibility of fire-flooding with large well spacing optimize the injection-production parameters.Result indicates that the cumulative oil increment reaches 13.1×10^4m^3 for the 3 low-efficiency wells after converting to fire-flooding development mode.The edge reserve was effectively produced,and the single-well cumulative oil production is up to 12.4×10^4m^3.The development mode with certain economic efficiency could meet the requirements of high production and less wells in offshore heavy oil reservoir with thermal recovery.This research could provide certain reference for the development mode conversion in the offshore heavy oil reservoir.