考虑储层层间非均质性的#br# 边水气藏气井见水时间计算模型——以普光气田下三叠统飞仙关组气藏为例

现有的边水气藏气井见水时间计算模型均未考虑储层层间非均质性的影响，较之于气井的实际见水时间，其计算结果存在着较大的误差，不能准确、有效地指导气井生产制度的调整和气藏控水技术措施的制订。为此，以四川盆地普光气田下三叠统飞仙关组边水气藏为例，开展了岩心并联水驱渗流实验；采用油气藏数值模拟的技术手段，研究了由于储层的层间非均质性引起的边水突进现象对气井见水时间的影响；在此基础上，引入突进系数来表征储层的层间非均质性，建立了考虑层间非均质性影响的多层合采边水气藏气井见水时间计算模型，并选取普光气田飞仙关组气藏5口井进行了实例计算。研究结果表明：①气藏储层的层间非均质性导致产生边水突进现象，并且层间非均质性越强，突进现象越严重、气井见水越早，渗透率最高的储层见水时间决定了气井的见水时间；②基于渗流理论，建立了考虑储层层间非均质性影响的边水气藏气井见水时间计算模型，其计算结果的相对误差介于－3.43%～4.70%，能满足工程误差的精度要求。结论认为，所建模型可以为准确计算多层合采边水气藏气井见水时间提供有效的方法，进而有助于边水气藏气井生产制度的调整和控水技术措施的制订。

A calculation model for water breakthrough time of gas wells in gas reservoirs with edge water considering the heterogeneity between reservoirs: A case study of the Lower Triassic Feixianguan gas reservoirs in the Puguang Gas Field

The existing models for calculating the water breakthrough time of gas wells in gas reservoirs with edge water ignore the effects of reservoir's interlayer heterogeneity, so their calculation results are more deviated from the actual water breakthrough time of gas wells. As a result, they cannot accurately and effectively guide the adjustment of gas well production system and the formulation of technical water control measures. In this paper, a water-flooding seepage experiment of parallel core was conducted by taking the gas reservoir with edge water of Lower Triassic Feixianguan Formation in the Puguang Gas Field of the Sichuan Basin as an example. Then, the effects of edge water inrush caused by the interlayer heterogeneity of reservoir on water breakthrough time of gas wells was analyzed by means of reservoir numerical simulation. Based on this, the inrush coefficient was introduced to characterize the interlayer heterogeneity of reservoir, and a model for calculating the water breakthrough time of gas wells in the commingled gas reservoir with edge water considering the influence of interlayer heterogeneity was established. Finally, five wells in the gas reservoir of Feixianguan Formation in the Puguang Gas Field were selected for case calculation. And the following research results were obtained. First, the the interlayer heterogeneity of gas reservoir results in edge water burst. And the stronger the interlayer heterogeneity, the more severe the edge water coning and the sooner the water breakthrough. The water breakthrough time of gas wells depends on the water breakthrough time in the reservoir with the highest permeability. Second, a model for calculating the water breakthrough time of gas wells in the gas reservoirs with edge water considering the influence of reservoir interlayer heterogeneity is established based on the seepage theory. And the relative errors of its calculation results is in the range of -3.43-4.70%, which can satisfy the accuracy requirement of engineering errors. In conclusion, this newly established model can provide an effective method for accurately calculating the water breakthrough time of the gas well in the commingled gas reservoir with edge water. Furthermore, it is conducive to the adjustment of the production system of gas wells in the gas reservoir with edge water and the formulation of technical water control measures.