CBM Field Proved Reserve Evaluation Based on Decline Curve Analysis and Type Curve: Case Study of Australia Surat CBM Gas Fields

Abstract

The proved reserve is the core asset in the CBM Field. The accurate proved reserve evaluation is very important for field development potential and development plan. Based on three producing field production data from Australia Surat basin, the proved developed producing reserve is evaluated on gas production decline curve analysis. Because of high permeability, most production well directly fit in exponential decline. Some production data fit in harmonic or hyperbolic decline according to the production data trends. The proved undeveloped reserve is evaluated based on type curve analysis and well placement plan in five years. The three kind type curves are build up by combined the three field production data analyses with reservoir simulations based on coal reservoir properties of three different fields. The three proved developed producing reserve profile is calculated by sum of the DCA production profile of different producing well in the three fields. The three proved undeveloped reserve production profiles are acquired by sum of the type curve production profiles in three fields according to the drilling plan in five years. Finally sum of the proved developed producing reserve and the proved undeveloped reserve in three fields is the proved reserve for three different fields. Based on the decline curve analysis and type curve simulation, the CBM field proved reserve evaluation procedures are build up and evaluation result is obtained. The similar methods and procedures also can be applied to other unconventional plays, such as shale gas etc.