Study On Reasonable Production Parameters And Production Factors Of Changjing - Weiyuan Shale Gas Well

By the virtue of the rapid development of shale gas exploitation, America has surpassed Russia and become the world’s largest producer of natural gas. While the Chinese shale gas reserve is close to the American’s, the Chinese shale gas shows great potential in the country’s natural gas exploitation. But Chinese shale gas formation has the feature of deep burial and high pressure, the amount of desorption gas is very little, which is far from enough to form an effective supplement to the gas well productivity. In order to exploit Chinese shale gas efficiently, it’s essential to study the influence of the production factors and forecast the gas well productivity. In other words, a production equation that can fit the characteristics of Chinese shale gas reservoir is required.On the foundation of consulting related articles, this paper studied the mechanisms of storage and transportation of shale gas. It has been observed that during the immigration of shale gas in matrix, the contribution of kerogen diffusion cannot be neglected. To imitate the actual gas transportation in the reservoir, we derived an equation having Darcy flow, gas desorption and kerogen diffusion. Combined this equation to the model of horizontal well with multi-stage hydraulic fracture, we get the solution of real shale gas well. Then we compiled computer program to simulate the production history of Changning-Weiyuan gas field. The result showed that the model can reflect the factor of shale gas wells. Finally, we used the parameter field from the simulation and forecast the production performance of shale gas wells. By studying the production performance in different poration, length of horizontal section, number of fracturing stages, well spacing and well array spacing, we found that under the normal pressure system, the suitable poration of gas well should be1/2of the early open flow capacity, while the ratio should be1/4under high pressure system. Considering the existing technical conditions, a shale gas field with the parameter of horizontal section length1000m-1200m, fracturing stage10-12, well spacing300m, well array spacing1800m will have an efficient exploitation.