石油钻采工艺
石油鑽採工藝
석유찬채공예
OIL DRILLING & PRODUCTION TECHNOLOGY
2015年
4期
67-71
,共5页
姜瑞忠%韩光伟%汪洋%徐攀登
薑瑞忠%韓光偉%汪洋%徐攀登
강서충%한광위%왕양%서반등
低渗气藏%渗流机理%滑脱效应%低速非达西%高速非达西%压敏效应
低滲氣藏%滲流機理%滑脫效應%低速非達西%高速非達西%壓敏效應
저삼기장%삼류궤리%활탈효응%저속비체서%고속비체서%압민효응
low permeability gas pool%seepage mechanism%slippage effect%low-rate non-darcy%high-rate non-darcy%pressure sensitivity effect
不同于常规气藏,低渗气藏由于其储层物性差、含水饱和度高的特点,其渗流机理更为复杂。以低渗储层为基础,对低渗气藏特殊渗流机理进行详细阐述;同时针对目前低渗气藏产能预测考虑因素不全、产能评价结果不够准确的问题,在拟启动压力梯度模型的基础上,依据稳态渗流条件下的气藏产能方程,综合考虑气体滑脱效应、低速非达西、高速非达西、压敏效应等多重非线性效应,结合渗流力学基本原理,推导了通用气体稳定产能预测方程,并进行参数敏感性分析。结果表明:低渗气藏的低速非达西效应、高速非达西效应、压敏效应都会使气藏产能变小;如果忽略其影响,将会造成对产能的乐观评价;其中启动压力梯度和压敏系数(尤其是异常高压储层)对气井产能影响显著,滑脱因子次之,高速非达西效应影响较小。通过实例验证了产能模型的正确性,可以用于指导现场实际开发。
不同于常規氣藏,低滲氣藏由于其儲層物性差、含水飽和度高的特點,其滲流機理更為複雜。以低滲儲層為基礎,對低滲氣藏特殊滲流機理進行詳細闡述;同時針對目前低滲氣藏產能預測攷慮因素不全、產能評價結果不夠準確的問題,在擬啟動壓力梯度模型的基礎上,依據穩態滲流條件下的氣藏產能方程,綜閤攷慮氣體滑脫效應、低速非達西、高速非達西、壓敏效應等多重非線性效應,結閤滲流力學基本原理,推導瞭通用氣體穩定產能預測方程,併進行參數敏感性分析。結果錶明:低滲氣藏的低速非達西效應、高速非達西效應、壓敏效應都會使氣藏產能變小;如果忽略其影響,將會造成對產能的樂觀評價;其中啟動壓力梯度和壓敏繫數(尤其是異常高壓儲層)對氣井產能影響顯著,滑脫因子次之,高速非達西效應影響較小。通過實例驗證瞭產能模型的正確性,可以用于指導現場實際開髮。
불동우상규기장,저삼기장유우기저층물성차、함수포화도고적특점,기삼류궤리경위복잡。이저삼저층위기출,대저삼기장특수삼류궤리진행상세천술;동시침대목전저삼기장산능예측고필인소불전、산능평개결과불구준학적문제,재의계동압력제도모형적기출상,의거은태삼류조건하적기장산능방정,종합고필기체활탈효응、저속비체서、고속비체서、압민효응등다중비선성효응,결합삼류역학기본원리,추도료통용기체은정산능예측방정,병진행삼수민감성분석。결과표명:저삼기장적저속비체서효응、고속비체서효응、압민효응도회사기장산능변소;여과홀략기영향,장회조성대산능적악관평개;기중계동압력제도화압민계수(우기시이상고압저층)대기정산능영향현저,활탈인자차지,고속비체서효응영향교소。통과실례험증료산능모형적정학성,가이용우지도현장실제개발。
The low permeability gas pools, different from conventional gas reservoirs, are characterized by poor reservoir physical properties and high water saturation, thus its seepage mechanism is even more complex. This paper sets forth in detail the special seepage mechanism of low permeability gas pools based on low permeability reservoirs. Meanwhile, in line with inadequate consideration factors for productivity forecast of low permeability gas pools and inaccuracy of the result of productivity assessment, this paper inferred a general equation for prediction of stable gas productivity, according to gas pool productivity equation under stable seepage conditions and activating pressure gradient model, and taking into full consideration the gas slippage effect and multiple non-linear effects like low-rate non-darcy effect, high-rate non-darcy effect, pressure sensitivity effect, in combination with seepage mechanic fundamentals. The result shows that the low-rate non-darcy effect, high-rate non-darcy effect and pressure sensitivity effect of low permeability gas pool all cause the gas pool productivity to become smaller. If these effects were neglected, then optimistic assessment would be made on productivity. Among which, the activating pressure gradient and pressure sensitivity coefifcient (particularly the anomalous high pressure reservoir) have a signiifcant effect on gas well productivity. The slippage factor plays a second role, and the high-rate non-darcy effect has the least effect. The examples conifrmed the correctness of the productivity model, which can be used for actual ifeld development work.