The main objective of this paper is to study the flow rate variation of the shale matrix while the gas is flowing from the shale matrix to the fracture network. For this a non-linear PDE equation has been developed, which involves the Klinkenberg Effect, Non-Darcy Flow and Adsorption/Desorption.
This paper mainly discusses about the modeling of gas flow from the matrix to the wellbore. The representation of the reservoir model includes a cube as a porous media i.e. it contains pore spaces in which free gas is stored and also the adsorbed gas. Now, the gas in the cube (both free gas and adsorbed gas) will start flowing out inside the matrix to the fractures (induced). Many of these cube representations are put together and connected to the well bore. In this paper, we have considered a dual porosity model. One porosity is the combination of matrix and natural fracture and the second porosity is the hydraulic fracture. For this model, a non-linear PDE equation has been developed which is then compiled using JAVA to develop a simulator for calculating the shale gas production, by considering the matrix as a source term. The production data that is obtained from this model will describe the unique characteristics of shale gas reservoirs.
A study on the role of natural fractures on production is done, by considering an updated dual mechanism and dual porosity model. Also the effect of hydraulic fractures on production has been studied. The obtained production results are also compared with the normal dual porosity model. Moreover, the results are also compared by developing a model in CMG-IMEX simulator.
The novelty lies in the fact that the proposed updated dual mechanism and dual porosity model provides better results when compared with the previous dual porosity models. This model will be helpful for the oil and gas industries to know the production rates during the lifetime of the reservoir.