Development of type curves for gas production from horizontal wells in conventional reservoirs

As the demand for natural gas has increased in the recent years, the need for forecasting reliable gas recoveries has also increased. Gas production type curves are one of the methods utilized to estimate future well performance.;The objective of this research has been to develop and evaluate production type curves for horizontal wells producing from natural gas conventional reservoirs. These curves can be used to predict the production performance for horizontal wells during preliminary evaluations, thus avoiding the need for costly and time consuming computer simulation.;Two set of type curves were developed using a finite-difference multi-layers reservoir model. They represent the two flow regimes associated with the horizontal wells, the early time liner flow and the late time pseudo-radial (elliptical) flow. They were presented in terms of dimensionless gas production and dimensionless time. Drainage shape was assumed to be rectangle since it is the more effective drainage area for horizontal wells. The dimensionless well length, the ratio of well length to reservoir length and pressure drawdown dimensionless parameter Xi were found to influence the type curves significantly.;In addition to developing the type curves, a range of parameters affecting the performance of horizontal wells including vertical-to-horizontal permeability and the length of the horizontal well compared to the extent of the reservoir were reviewed. Porosity and drainage area size were found to have no affect on type curves. On the other hand, reservoir thickness and horizontal permeability were found to have minor impact on the shape of the type curves