页岩气藏动用储量计算方法评价——以涪陵页岩气区块为例

Evaluation on Calculation Methods of Produced Reserves in Shale Gas Reservoirs——Taking Fuling Shale Gas Block as an Example

页岩气作为一种重要的非常规资源,可以缓解能源短缺,其高效开发保证了油气的可持续发展。由于页岩气主要以游离或吸附状态存储于页岩层或泥岩层中的特殊性,导致常规的储量计算方法已经无法计算,然而储量的准确计算是制定页岩气藏开发方案必不可少的一步。因此,考虑页岩气储集条件的特殊性,分析几种考虑吸附气的储量计算方法,如流动物质平衡法、Palacio法、Ibrahim法及Anderson法,并将其应用到涪陵页岩气田中。结果表明:68井组7口生产井单井动用储量在(6.0428~12.1747)×10^(8) m^(3)之间,平均为9.211 6×10^(8) m^(3);吸附气占比39.9%,游离气占比60.1%;吸附气采出程度为11.87%,游离气采出程度为17.85%,并且流动物质平衡法、Ibrahim法更加适用于页岩气藏储量计算。

As an important unconventional resource, shale gas can alleviate energy shortage, and its efficient development guarantees the sustainable development of oil and gas. Due to the particularity of shale gas stored in shale or mudstone layers in a free or adsorbed state, conventional reserves calculation methods cannot be used.However, accurate calculation of reserves is an essential step in formulating shale gas reservoir development plans. In this article, considering the particularity of shale gas storage conditions, several calculation methods considering adsorbed gas reserves were analyzed, including the flowing material balance method, the Palacio method, the Ibrahim method and the Anderson method, and they were used to calculate the reserves of Fuling shale gas field. The calculation results showed that the single well produced reserves of 7 production wells in the 68 well group was between 6.042 8×10^(8) m^(3) and 12.174 7×10^(8) m^(3), with an average of 9.211 6×10^(8) m^(3);the proportion of adsorbed gas was 39.9%, and the proportion of free gas was 60.1%;the degree of recovery of adsorbed gas was 11.87%, the free gas recovery degree was 17.85%, and the flowing material balance method and Ibrahim method were more suitable for the calculation of shale gas reserves.