Investigate Means of Stimulating Tight Gas Sands in the Presence of Weak Barriers by Modified Hydraulic Fracturing Techniques

摘要

The objective of this program is to devise a practical technique or techniques of inducing deeply penetrating fractures in tight gas formations bounded by base rock and/or overlain by an overburden rock that are not barriers to fracture migration. These formations are not amenable to 'successful' stimulation by hydraulic fracturing as practiced today. Post- fracturing well tests reveal that a high percentage of fractures do not stay confined to the productive interval. By identifying these 'weak barrier' zones, through the use of in-situ stress measurements, and by developing modified hydraulic fracturing techniques that will control fracture migration, the fracturing process could be more successful in improving gas production from tight formations. The four modified hydraulic fracturing techniques mentioned included: (1) Fracture Initiation Placement, (2) Fracture Packing with Light-Weight Bridging Agents, (3) Controlled Process Zone Fracturing, and (4) Electrical Fracturing followed by hydraulic fracturing. The four techniques were evaluated for technical and economic feasibility by performing laboratory simulations, field fracturing implementations, and analytical modeling.