Benefits of the Novel Fiber-Laden Low-Viscosity Fluid System in Fracturing Low-Permeability Tight Gas Formations

摘要

Most of the low-permeability tight gas market that is treatedrnby low-viscosity slickwater fracturing treatments results inrnineffective propped fractures due to rapid proppant settling.rnCurrently hybrid fracturing and ultra-lightweight proppants arernemployed for improving performance of slickwater treatments.rnThe hybrid fracturing methodology uses a combination ofrnlinear and crosslinked gels to improve proppant placement.rnThe disadvantages of existing lightweight proppants are theirrnhigh cost and applicability only to reservoirs characterized byrnlow closure stresses.rnNovel fiber-laden low-viscosity fluid technology has beenrndeveloped to improve proppant transport for hydraulicrnfracturing in low-temperature tight gas formations. Such arnsystem creates a fiber-based network within the fracturingrnfluid that decouples proppant settling from fluid viscosity.rnThis network entangles proppant, dramatically reducesrnproppant settling, and provides a mechanical means torntransport and place the proppant at greater distances from thernwellbore. An additional advantage of the new system lies inrnfiber degradability, which leads to a nondamaged fracturernconductivity with time.rnFluid rheology of fiber-laden fluids was measured over arn150–230 °F temperature range under various fiber loadings.rnStudies showed that under bottomhole temperature and fluidrnpH fiber decompose and form a water-soluble species. Duringrnfiber degradation, the permeability of the fiber-laden systemrnapproaches the value of permeability for the baseline systemrnwithout fiber. Compatibility study of the degradationrnbyproducts with formation water showed no precipitaternformation in high salinity environments.rnThe results demonstrate that the new fiber technologyrnensures uniform proppant placement within a long fracture,rnprovides permeability equal to pure proppant pack values, andoffers higher production rates in comparison withrnconventional fracturing treatments.