Developments in Efforts to Replace Borate Crosslinked with High Viscosity Friction Reducers. Part I: Laboratory Tests

Abstract The development of advanced hydraulic fracturing fluids is crucial to enhance hydrocarbon recovery from tight formations characterized by high temperatures and stress. Vitthal et al. (2024) described the work on developing a fluid applicable to conventional fracture design using a High Viscosity Friction Reducer (HVFR) based on Polyacrylamide (PA) polymers, which are well-established in unconventional shale gas at higher polymer loadings, aiming to replace decades-old Borate Crosslinked (BXL) systems. Building on this work, this paper describes the effort in designing HVFR fluid for its implementation in tight gas Miqrat and Barik formations, where commonly, the BXL system is used in conjunction with hybrid and conventional Tip Screen Out (TSO) frac designs. The main advantages of a modified HVFR system are minimal proppant pack and formation damage, generating fracture with larger conductivity and longer effective length, ultimately resulting in improved well performance. HVFR is less sensitive to water quality and easier to mix in the field compared to BXL fluid, making it an ideal candidate to simplify and improve operational efficiency. High-temperature reservoir conditions, up to 290°F, were evaluated in the laboratory, and it has been shown that HVFR possesses a high proppant-carrying capacity and robust stability, resulting in lower pipe friction loss. These characteristics are anticipated to provide a healthier alternative to traditional BXL fluids, thereby unlocking new potential applications in different reservoir types. Regained conductivity, regained permeability, and leak-off tests were conducted to assess HVFR's ability to sustain proppant pack conductivity and preserve formation permeability. Extensive rheology tests were performed on various HVFR products to identify the most effective one, determine the optimal polymer concentration that mimics BXL, and establish the correct breaker dosage. Additional tests with formation water, hydrocarbon, and other contaminants were conducted to ensure full compatibility with HVFR. Preliminary results indicate significant advantages over BXL fluids, potentially extending to a reduced environmental impact. This paper explores the formulation, laboratory test results, and implications of HVFR in creating new opportunities for reservoir stimulation. The review of the step-by-step workflow applied in the evaluation of this novelty application of HVFR fracturing fluid consists of (a) fluid formulation through laboratory testing presented in this paper, (b) field implementation in different reservoirs (in Part II), and (c) future potential extension to offshore high permeability reservoir. The reduced damage to the proppant pack would represent an enabler for the utilization of lower-tier proppants without compromising production uplift, unlocking new resources in the Khazzan and Ghazeer fields through its application in both vertical and horizontal wells. Finally, it provides a tangible example of how advancements in unconventional technology in North American plays can be adapted to conventional and high-value wells, where lower risk tolerance often hinders fast technological progress.