同步回转排水采气工艺的探索应用

Exploration of synchronal rotary drainage gas recovery technology and its application in liquid loading wells and water flooded wells of Daniudi Gasfield

为解决鄂尔多斯盆地大牛地气田低压低产气井容易发生积液水淹,而采用常规泡排工艺无法维持正常生产的难题,探索试验一种同步回转排采工艺对积液水淹井进行抽吸。将同步回转现场试验结合复产机理,分别针对积液井和水淹井建立不同工况条件下的复产评价模型,明确了该工艺在积液水淹井的复产条件,即:①积液井的复产条件为抽吸流量大于气井全井段的最大临界携液流量;②水淹井的复产条件为抽吸举升压差大于水淹液柱压力。通过对6口积液水淹井现场验证分析得出:①同步回转工艺能解决积液井和部分水淹井的排液难题,可为致密气藏的排水采气开发提供的新的思路;②复产评价模型计算准确可靠,得出的3口积液井和1口水淹井复产成功,另外2口水淹井复产失败的结论与实际试验结果一致,评价准确率为100%,从机理上可指导同步回转排采工艺的推广应用。

The low pressure and low yield gas wells in Daniudi Gasfield are easily subjected to liquid loading and water flooding and their normal production cannot be maintained only by using the conventional foam drainage gas recovery technology.In order to solve this problem,a synchronal rotary drainage gas recovery technology used for the suction of liquid loading wells and water flooded wells was explored and tested in this paper.Then,the production resumption evaluation models used for liquid loading wells and water flooded wells in different working conditions were established by means of field synchronal rotary tests,combined with the production resumption mechanisms.And the production resumption conditions of liquid loading wells and water flooded wells by using the synchronal rotary drainage gas recovery technology were determined as follows.First,the production resumption condition of liquid loading wells is that the suction flow is higher than the maximum critical liquid carrying flow of the whole gas well.Second,the production resumption condition of water flooded wells is that the suction lift pressure difference is higher than the pressure of the water flooded fluid column.Finally,this technology was verified on site at 6 liquid loading wells and water flooded wells.It is concluded that this synchronal rotary drainage gas recovery technology can solve the liquid drainage difficulties of liquid loading wells and some water flooded wells,and provide a new idea for the drainage gas recovery of tight gas reservoirs.In addition,the calculation results of the production resumption evaluation models are accurate and reliable.The production of 3 liquid loading wells and 1 water flooded wells are successfully resumed and the evaluation on the production resumption failure of the rest 2 water flooded wells are accordant with the actual test results.Obviously,the evaluation accuracy is 100%.The research results can provide the guidance from the viewpoint of mechanism for the popularization and application of the synchronal rotary drainage gas recovery technology.