SHALE OIL AND GAS FRACTURING METHOD WITH LOW ENVIRONMENTAL IMPACT

摘要

A method is provided for lowering the migration of a hydraulic fluid additive within a hydrocarbon-bearing formation penetrated by a well when producing hydraulic fracturing. Many chemical agents currently in use with water/sand (or other proppants) mixtures could pose human and animal health risks if these chemicals migrate from the shale beds into the environment contaminating the water table, rivers, streams and lakes. The fracturing fluid chemical additives employed are designed to be retained or anchored in or near the deep shale layers and are prevented, or greatly delayed from upward migration. Specifically, chemical additives required for proper fracturing fluid performance are covalently chemically bonded to inert particulate materials (e.g. silica having a particle size less than 2000 microns). The fracturing fluid chemical additives are thereby able to perform their function in the shale fracturing process, and thereafter become nearly permanently trapped in the shale layers protecting the environment above.