Dynamic Analysis Of Carboniferous Gas Reservoirs In Hot Spring

Situated in the Luojiazhai structure of northeastern Sichuan Basin, Wenquan carboniferous gas reservoir can be divided into two relatively independent reservoirs, the hanging wall reservoir and the footwall reservoir. As for the hanging wall reservoir, it went into production at the beginning of2003. However, after being exploited for more than ten years, this reservoir has proceeded to the late development stage during which, the pressure, the flow rate, as well as the producing energy are tending to decline. In order to solve these problems, the current goal is to extend producing time and to enhance ultimate recovery efficiency. As for the footwall one, it is in the ascending period since it has been putting into produce for less than three years. Therefore, we should focus on the distribution of gas and water, the analysis of connectivity and the convergence of reserves for formulating a rational development plan, which is the foundation of properly exploitation.Combined informative field static information with dynamic production data, the following conclusions can be achieved. To begin with, the possible depth of gas water contact of the hanging wall reservoir is from-4334to-5224m and the depth of the footwall reservoir one is at an elevation of-4800m. Additionally, the hanging wall reservoir and the footwall reservoir are two relatively independent pressure systems. What’s more, by means of comparing the results through pressure drop and cumulating producing rate methods, the dynamic reservoir reserves and the single well controlled reserves have been acquired in a reliable way. Moreover, aimed at the hanging wall reservoir, traditional and modern methods for analyzing production decline are utilized to obtain the declining parameters, such as the residual reserves of single wells, abandonment time, dynamic reserves and permeability. Furthermore, the productivities of gas wells are calculated for further production allocation. After being compared by several prorating methods, relatively reasonable production rates for each well can be achieved finally. Overall, these effectively dynamic analyses can make a great theoretical contribution to guaranteeing the reasonability of formulating a reservoir development plan.