中江气田地面高效集输关键技术与应用

针对中江气田滚动开发、快速上产导致管网压力高、低压低产井生产困难、同井场井间干扰制约低压井产能释放等问题,开展了针对管网、站场、气井的3项地面高效集输关键技术研究与应用。首先,基于现有管网开展多方案结构优化模拟,建立了8字型“枝状+环状”复合型管网,集输能力提升两倍、气田远端回压降低0.5 MPa,确保了天然气顺利外输;其次,针对轴向分布低压低产气井,开展了5～10 km多节点增压半径技术经济界限系统评估,形成中江气田10 km长半径增压方案,覆盖范围提升30%,建设成本降低25%,实现狭长带状分布气井低成本增压;最后,针对同井场高低压气井研制了“活动式+低压差”引射装置,将常规引射压差由3.0～5.0 MPa降低至0.4～1.0 MPa,实现了在无外部动力源条件下,同井站相对高压井对低压井的引射增压,被引射低压井油压最高降幅达0.9 MPa、产量提升20%～140%,避免了同井场高压气井对低压气井生产的抑制;中江气田地面高效集输关键技术有效支撑了气田产量目标的顺利实现、保障“采的出、输得走”。

Key Technologies and Applications of High-efficiency Surface Gathering and Transportation in Zhongjiang Gas Field

Aiming at the problems of rolling development of ZJ Gas Field, high pipeline network pressure caused by rapid production ramp-up, difficulty in production of low-pressure and low-yield wells, and interference between wells at the same well site restricting the production release of low-pressure wells, three surface high-efficiency measures for pipeline network, station site and gas well, research and application of key technologies for gathering and transportation were carried out. Firstly, multi-scheme structural optimization simulation was carried out based on the existing pipeline network, and a figure-8 "branch + ring" composite pipeline network was established, which doubled the gathering and transportation capacity and reduced the back pressure at the far end of the gas field by 0.5 MPa, ensuring natural gas second, for axially distributed low-pressure and low-yield gas wells, a systematic evaluation of the technical and economic limits of 5$sim$10 km multi-node booster radius was carried out, and a 10 km long-radius booster scheme for the ZJ Gas Field was formed, which increased the coverage by 30% and reduced the construction cost by 25%, to realize low-cost pressurization of gas wells distributed in narrow and long strips; finally, for the high and low pressure gas wells in the same well site, a "movable + low pressure difference" ejector device was developed, which reduced the conventional ejection pressure difference from 3.0$sim$5.0 MPa to 0.4$sim$1.0 MPa, realizing the injection booster of the low-pressure well relative to the high-pressure well in the same well station without the external power source. The high-pressure gas well at the well site inhibits the production of the low-pressure gas well; the key technologies of efficient surface gathering and transportation in the ZJ Gas Field effectively support the smooth realization of the gas field production target and ensure the "production and output".