ABSTRACT
Significant potential natural gas resources remain in low permeability marginal reservoirs of the Appalachian Basin. Horizontal well as an alternative to fractured vertical well, has a significant potential to enhance the recovery from the low permeability gas reservoirs. This paper addresses the potential contribution of horizontal wells to increasing the economic recovery from the low permeability gas reservoirs.
The selection of horizontal well over vertical well in low permeability gas reservoirs must be based on engineering and economic feasibility evaluations. The accurate prediction of production rates is one of the most important variables for feasibility evaluation of horizontal wells. It is, therefore, desirable to develop and evaluate simple but reliable methods for predicting the production performance of the horizontal wells. The production performance of horizontal wells completed in the low permeability gas reservoirs can be predicted by utilizing production type curves without the need for costly and time consuming computer simulations.
The application of the production type curves and the issues concerning the production performance of horizontal wells in the low permeability gas reservoirs are discussed. In addition, pre-stimulation production data from a horizontal well in West Virginia is compared with the predicted results from the type curves in order to evaluate the applicability of the type curves.
