新疆柯克亚西42-西52凝析气藏单井注气吞吐解堵技术

Single Well Gas Injection Swallowing-spitting Plug Removal Technique Used for Xi42-Xi52 Condensate Gas Reservoir of Kekeya Field in Xinjiang

新疆柯克亚凝析气田勘探初期遭受了 3口喷井的破坏和其后近 2 0年的衰竭式开采 ,地层压力大幅度下降 ,地层反凝析现象严重 ,特别是近井地带压降漏斗的存在 ,析出的凝析油更多 ,严重污染了井筒周围的储层 ,造成渗流阻力增大 ,致使多口气井停产或无法正常生产 ,影响气藏的整体开发效果。文章应用多组分数值模拟技术 ,计算不同天然气注入量对反凝析液的“反蒸发”和驱扫效果 ,模拟结果表明 :注气量越多 ,越能有效地解除近井地带的反凝析污染。经矿场实验 ,注气量在 10 0× 10 4～ 15 0× 10 4m3 时 ,单井吞吐注气解堵效果较好 ,同时 ,也可明显地改善地层的渗流性能和提高气藏的储量动用程度。

In Kekeya condensate gas field in Xinjiang,the formation pressure decreased greatly and the retrograde condensation was serious because of being destroyed by three flowing wells in the initial stage of exploration and being suffered natural depletion exploitation for near twenty years after it.Especially owing to the occurrence of pressure drop funnel near the wellbores,much more condensate has been released and the reservoirs around the wellbores have been seriously polluted,which causes the increase in percolation resistance and the off-production of many gas wells or their being unable to be normally put into production,thus influencing the overall development results of the gas reservoirs.The effect of different gas injection rates on the'Retrograde evaporation'and removal of the retrograde condensation liquids was calculated by applying multicomponent numerical simulation technique.The results of simulation indicated that if more gas was injected,the retrograde condensation pollution near the wellbores might be more effectively removed.Through testing in field,it was pointed out that when the gas injection rates are from 1000×10 3m 3 to 1500×10 3m 3,the single well gas injection swallowing-spitting plug removal results are good;and the percolation behaviors of the reservoirs may be obviously improved also,thus raising the movable reserves in the gas reservoirs.