This paper reports the completion of a two-lateral well in the Williston basin where produced water (PW), filtered but otherwise untreated, was used throughout the slickwater and crosslinked components of approximately 60 hydraulic-fracturing stages. Proppant was placed successfully in all perforated zones by use of a hybrid design that used 7 million gal of water (of which 2.2 million gal was crosslinked). This paper will concentrate on the development and implementation of a metal-crosslinked fracturing fluid that showed excellent stability.
Introduction
The demand for an economical approach to reuse water from oilfield operations—namely produced, flowback, and nonpotable sources—is not a new concept. In slickwater fracturing, reuse of PW is a solved problem, thanks to the ready availability of synthetic friction reducers that are efficient even in heavy and unpredictable natural brines. Here, the physical chemistry of the system (a soluble polymer reducing pipe friction) is fairly straightforward and the key innovations driving successful friction reduction in PW were easy to identify and import from polymer science once the failure mechanisms for the parent polyacrylamides in PW were understood.
