Completion Strategy Alteration on an Overpressured Field Based on Geomechanical Modeling and a Geomechanics Based Fracture Design

Abstract

Hydraulic fracturing as an approach of oil and gas recovery intensification in clastic formations has long been well known and recognized from technological and economical sides. However, in spite of the obvious advantages of hydraulic fracturing procedure, the method has its drawbacks which decrease the final oil and gas productions. One of these disadvantages is a fracture breakthrough into the adjacent layers with following water cut increase and reduction of cumulative oil and gas production and production rates. Bearing in mind the geological structure of the explorational targets in this paper, the problem becomes more relevant. The presence of an abnormally high formation pressure in the reservoir, which exceeds the surrounding shale's pressure, and the shale barrier, which does not provide a sufficient stress barrier, promotes possible breaks of fractures into the overlying water-bearing zone. Owing to the simulation of hydraulic fractures based on the geomechanical model, it was possible to implement the hydraulic fracturing strategy and planning, taking into account the understanding of the geomechanical parameters and the stress-strain state of the medium, in which it was possible to avoid breakthroughs of hydraulic fractures into the overlying water-saturated formation. In addition, it is shown that outwardly similar development objects may require radically different approaches to well completion.