多层合采井产量劈分方法及在大牛地气田的应用

大牛地气田多层合采气井历年产量剖面测试数据差异较大，常规劈分方法难以适用，且大量未测试井需要开展产量劈分工作。针对合采井产量劈分问题，结合大牛地气田合采井生产动态数据，提出了累计产量剖面法；利用突变理论建立了合采气井产量劈分模型，得到了合采井各层产量劈分系数。研究表明，与产剖测试数据相比，累计产量剖面法能得到较稳定的产量剖面，计算方差可减小70%以上；与KH值劈分法相比，突变法平均误差能降低50%以上，更接近稳定的产量剖面劈分结果。因此，累计产量剖面法能削弱产剖测试异常对劈分结果的影响，突变法更适用于大牛地气田合采气井产量劈分计算。研究成果可提高大牛地合采井各层的动态储量、泄气半径等参数计算的准确度，为气田开发提供技术支持。

Commingled producing well production split method and its application in Daniudi Gasfield

The historical production profile testing data of commingled gas producing wells in the Daniudi Gasfield varies greatly, so the conventional production split method is not applicable. In addition, a great number of untested wells are in urgent need of production split. The cumulative production profile method was put forward based on the production performance data of the commingled producing wells in the Daniudi Gasfield to deal with the production split of commingled producing wells. Then, the production split model for commingled gas producing wells was established according to the catastrophe theory. Finally, the production split coefficient of each layer in a commingled producing well was calculated. It is indicated that compared with the production profile testing data, the cumulative production profile method can provide more stable production profile and the calculation variance can be reduced by over 70%. And compared with KH production split method, the catastrophe method is over 50% lower in average error, so it is closer to the stable production profile split result. To sum up, the cumulative production profile method can weaken the influence of production profile testing abnormal on the production split result, and the catastrophe theory is more applicable to the production split calculation of commingled gas producing wells in the Daniudi Gasfield. The research results are conducive to improve the calculation accuracy of dynamic reserves, gas drainage radius and other parameters of each layer in the commingled producing wells of the Daniudi Gasfield, providing technical support for gas field development.