Effect of reservoir characteristics on the productivity and production forecasting of the Montney shale gas in Canada

Abstract

Shale gas is a typical unconventional gas trapped in a tight shale formation, which is considered as a source as well as reservoir rock. Therefore, the productivity of shale gas is closely related to the reservoir parameters making it very important to understand the characteristics of shale reservoirs. In this study, the production data of Montney shale was analyzed and the impact of the reservoir characteristics on the productivity was quantified. The reservoir characteristics can be divided into the reservoir quality (RQ) and completion quality (CQ) parameters. The productivity of shale gas, which is defined as the production decline variables, such as the peak monthly rate (PMR), the initial decline rate, and the decline exponent, was compared with the RQ and CQ.Among the CQ parameters, the brittleness index (BI) was found to affect the overall decline trend in production and had a qualitative correlation with the initial decline rate and decline exponent. Moreover, among the RQ, the total organic carbon (TOC) is closely related to the PMR and the amount of organic carbon (S1) already generated as hydrocarbon is strongly correlated with the initial decline rate and the decline exponent, especially in the transient linear flow regime. Therefore, it is possible to quantify the effects of the organic carbon contents on the productivity of shale gas and estimate the production in the transient linear flow regime.