Developments in Efforts to Replace Borate Crosslinked with High Viscosity Friction Reducers. Part II: Field Trials in Miqrat and Barik Sandstones

In the last 14 years, over 100 wells have been hydraulic fractured during the development phase of Khazzan and Ghazeer fields, Block 61, Oman. The primary stimulation approach consisted in massive single stage Tips Screen Out (TSO) hydraulic fracturing treatments with borate crosslinked (BXL) as fracturing fluid, also multistage verticals and horizontals have been applied in various occasions. While BXL fluids have been the standard fluid of choice for conventional fracturing for several decades because of their excellent proppant carrying capacity and minimal leak-off properties, reflected in the ability to generate large and conductive fractures, they also have a complex and fragile chemistry requiring specific attention to water quality and additive dosage, making their design and application a complex task. Additionally, it is well known and accepted and perhaps dismissed because of their routine application in the industry, that BXLF can cause considerable proppant pack and formation damage, especially in good quality formations typical of this sector, consequently affecting overall well performance. To tackle this dilemma, the development of a more operationally friendly and less damaging substitute to BXL fluid is an ongoing industry effort that gained traction in recent years because of technological progress in fracturing fluid used in unconventional shale gas. This paper leverages this unconventional fracturing fluid technology progression and describes the field implementation of High Viscosity Friction Reducer (HVFR) fluid at high polymer concentration as a simpler to mix fluid, more stable at different water quality, and less damaging. Extensive laboratory process is described in Part I of this paper and was performed to properly formulate the fluid recipe and providing analogous performances to BXL fluid regarding viscosity, proppant transport and suspension capacity, and stability in high-temperature reservoir conditions. This paper, Part II, describes the field implementation experiments in the Ghazeer field that confirmed an effective fluid and proppant placement, with leak off and fluid efficiency equivalent to standard BXL fluid, while improving operational and well performance. This paper examines the equipment readiness before field mobilization, results of frac diagnostic injections and frac treatments, the QAQC implemented on location, and the initial well-testing outcomes comparatively quantifying the formation damage linked to BXL fluid versus the modified HVFR. The results underscore the capability of the novel fluid to enhance well performance and durability by reducing damage, representing substantial progress in hydraulic fracturing techniques for tight formations and the future way forward suggested for implementing conventional formations with higher permeability.