沈建文*， 王旭东
（ 中石化西南工程有限公司钻井工程研究院； ）
摘要： 考虑气体溶解度、气体滑脱、油基钻井液体积系数，在多相流动模型的基础上，提出了析剩气体模型，分析了环空多相流动空隙率变化规律；采用显示差分法对模型求解。计算结果表明，井底发生持续气侵过程中，考虑溶解度可产生环空段0空隙率现象；回压增大、气侵率减小及油基比减小均使环空0空隙率井段增加；碳酸气体侵入井底时，回压从0.1MPa增至4.0MPa，环空0空隙率井段从1000m增至2700m，较不考虑0空隙率，环空空隙率最大误差达21.22%；CO2气体侵入井底时，油基比从0.1增至5，环空0空隙率井段从1500m增至2250m，较不考虑0空隙率，环空空隙率最大误差达26.57%。
关键词： 溶解度；0空隙率；气液两相；钻井；环空
SHEN Jianwen*， WANG Xudong
（ Drilling engineering institute, Sinopec Southwest Petroleum Branch； ）
Abstract： With consideration of the factors such as gas solubility, gas slippage, volume factor, on the basis of multiphase flow model, the concept of 0 gas flow is proposed in annulus, a residual gas model for gas-liquid is proposed. The method of residual gas analysis is proposed to calculate the void fraction in annulus. The mode is solved by the difference method. In the calculation example, when gas influx occurs in continuous in bottomhole, there is a 0 gas flow appear with considering the solubility. With the increase of back pressure and the decrease of gas influx rate, oil base ratio, the length of 0 gas low is increased in annulus. The length of 0 gas flow in annulus increases from 1000m to 2700m with the increase of back pressure from 0.1MPa to 4.0MPa When carbonic gas influx occurs at bottomhole,. The maximum void fraction error is 21.22%. The length of 0 gas low in annulus increases from 1500m to 2250m, with the increase of oil bas ratio from 0.1 to 5MPa. The maximum void fraction error is 26.57%When CO2 gas influx occurs in bottomhole.
Keywords： solubility; 0 gas flow; gas-liquid two-phase; drilling; annulus
作者简介： 沈建文(1974—)，男，高级工程师，主要研究方向为超深高温高压环境下的安全高效钻井技术
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