ABSTRACT of Presentation
Over the last ten (10) years, the shale revolution in North America has shown the great potential that exists in the shale plays and their potential impact in altering the energy picture, not only in North America, but worldwide. The magnitude of the resource and production data were very encouraging. Early data, however, showed rapid decline in the first year (as much as 90%), raising some concerns about the long term viability of the predicted Estimated Ultimate Recovery (EUR) values for these wells.
To investigate the causes and impact of the observed large annual decline in the first year, multiple technical studies were undertaken. As a result of these studies, the industry discovered that production practices led to such rapid decline. Methods to mitigate and reduce these large annual declines and preserve the predicted EUR’s were developed and production practices were adjusted. The resulting approach, referred to as “Drawdown Management”, was developed and strictly applied in majority of shale plays (gas or oil). This new drawdown management methodology resulted in reducing the first year production decline to 60% and sometimes less.
In this discussion, we will review the elements that were found to greatly impact shale well productivity along with field results showing how this impacted the predicted EUR from these wells. Furthermore, we will outline the relation between this approach of production management and the need for re-fracturing in shale plays.