气测速敏中气体滑脱效应的校正

气藏需用气体作为实验流体来测量储层的速敏性,按液测速敏的实验步骤和计算方法,则气测速敏指数和临界流量因受气体滑脱效应的影响而不准确.采用二次气测速敏实验步骤和新的计算方法可有效地校正气体滑脱效应影响,精确计算出气藏储层的速敏指数和临界流量.该方法运用于长庆上古致密砂岩气藏的速敏评价实验中,结果表明:速敏指数比常规实验方法要小,临界流量比常规实验方法大,储层的速敏损害程度由以前认为的中等水平变为弱水平,这与致密砂岩储层地质特征更相符合.

CORRECTING GAS SLIPPAGE EFFECT IN GAS SPEED SENSITIVITY EXPERIMENT

Gas field needs gas as experimental fluid to measure the speed sensitivity of reservoir. If using the steps and calculating method of the liquid speed sensitivity experiment, the index of gas speed sensitivity and critical velocity is not accurate because of the influence of the gas slippage effect. Gas slippage effect can be corrected effectively, and the index of gas speed sensitivity and critical velocity can be calculated accurately by means of twice experiment steps of gas speed sensitivity and new calculating method. By using this method in the speed sensitivity experiment of Neopaleozoic tight sandstone in Changqing gas field, the results show that the index of gas speed sensitivity is smaller and critical velocity is bigger than that of normal experimental method. The degree of speed sensitivity damage in the reservoir becomes weak level compared with middle level as recognized before. This result corresponds with the geological features of the tight sandstone reservoir.