| Coal Bed Methane Development Optimization |  |
This page will review Coal Bed Methane (CBM) development optimization, and the challenges associated with it. It will show how to properly place a constraint on gas production, as well as how to shift wells in time in order to fit these constraints.
Creating the Network
A flow schematic is easily created in WellSpring to represent the field wells and facilities, as well as type wells.
Type Wells/Type Curves
The hundreds of proposed wells are based on typical production represented by a "Type Curve". This is the decline curve specified for the Type well.
Constraints
From the calc menu, run an Unconstrained calculation. This will show potential production uncurtailed. Actual production potential is higher than the facilities can handle, so not all wells can be brought on at the same time.
Individual constraints can be added at each of the facility nodes via the data tab, the network tab, or the data menu. When WellSpring re-calculates the model, it will shift individual wells in time in order to meet and honor the constraints.
After the optimization, the field is producing within the facility constraints.
Results - Incremental Scenario Comparison
This model can then be used to compare different facilities sizes. We can create a second scenario with compression capable of 15 mmcf/d.
The plot below shows the 10 mmcf/d case subtracted from the 15 mmcf/d case.
With the respective capital and operating costs entered for these scenarios, an incremental comparison of the economics can be calculated to evaluate the alternatives. In this example, the production is accelerated, but it doesn't justify the increased capital for the larger facilities.
