A Faster Cleanup,Produced-Water-Compatible Fracturing Fluid:Fluid Designs and Field Case Studies

摘要

Natural gas reservoir development continues at a record pace in North America.Additionally,reservoir pressure depletion and declining quality of reserves have resulted in escalating drilling,completion,and workover costs per unit of gas produced.This in turn forced industry to focus on increasing efficiency by refining completion processes and field operations to make wells commercially viable.Strategies such as multiple-zone commingled completions,the selection of fluids and additives to maximize hydraulic fracture effective length and conductivity,and fluid recycling/handling are but a few strategies employed.Additionally,operating companies have been seeking other cost-control measures,including reducing the number of additives in fracture fluids and minimizing disposal costs of produced waters by recycling and by using them as the base for completion and fracturing fluids.Because of the uncertainty of the produced water impurity,composition,and concentration,it is extremely challenging to make a fracturing fluid compatible with produced water.Together with the need to gel produced water,the demand for more conductive fractures,along with the capacity to create sufficient fracture geometry,has led to the development of a unique surfactant-based system relatively insensitive to most produced waters,and even to some high-density brines.Fluid chemistry modifications employed to enhance performance allowed for reductions in mix-water and fluid-handling costs,shortened flowback/cleanup time,and provided equal or improved post-fracture production response.This paper focuses on a description of the fluid chemistry and performance along with numerous fracture treatment applications with a variety of mix-waters.