Production Performance Analysis of Shale Gas, Coal Bed Methane, and Tight Gas Reservoirs With Different Well Trajectories And Completion Techniques

Abstract

In the last decades, the exploitation of unconventional gas reservoirs such as coalbed methane, shale gas, and tight gas has become an ever increasing part of world gas supply. With state of the art technology and high gas prices, these resources can be developed by achieving economical gas production. The economic viability of many unconventional gas developments hinges on effective stimulation of extremely low permeability rock by creating very complex well trajectories and fracture networks. Each unconventional gas reservoir is unique and needs special interests to be characterized accurately. Ordinarily, it is very difficult to characterize them and choose the right recovery techniques. Accurate stimulation and determination of the unconventional gas reservoir systems plays an important role to produce natural gas commercially and optimize the recovery properly. The main effort of this study is to investigate the well performance of coalbed methane, shale gas, and tight gas reservoirs with different well configurations and stimulation scenarios. In order to obtain the outcome of these analyses, a 3D layered geological model with a 25×25×52 grid having four different zones with different thicknesses was constructed and modified for each reservoir system with different characteristics as a means of providing some distributed properties by Petrel. On the other hand, the reason the models were created with similar areal extend is to compare the gas in place and recovery of each system. A series of reservoir simulation were performed by Eclipse as the commercial numerical simulator with two types of porosity system; dual porosity for coalbed methane and shale gas reservoirs, single porosity for tight gas reservoir. In some reservoir systems, hydraulic fractures were represented and included into the model by local grid refinement and permeability multiplier facilities of Eclipse for vertical, horizontal, and multilateral well types. The objective of the study can be divided into two parts: The first is to decide which well configuration provides better production performance and how much gas are obtained with improved production from different types of unconventional gas reservoirs. The other goal is to determine what the important factors and limitations for modeling and simulation of unconventional gas reservoirs are.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014