Evaluation of Design Criteria for Gravel Pack and Hydraulic Fracturing Fluids

摘要

Visco us gravel-carrier and highly viscoelastic crosslinked fluids used in gravel packing and hydraulic fracturing respectively often contain polymers which are capable of damaging the formation. Thus after placement, the polymers must be degraded by gel breakers and be removed from the wellbore or formation to prevent formation damage, facilitate good regained conductivity and permeability of the proppant pack, which is essential for good well hydrocarbon production. The action of the gel breaker must be co ntrolled; it must not act too fast to break the gel, causing premature deposits of the proppant in the tubings before getting to the desired zone, creating early screen out, thereby jeopardizing the job. The gravel carrier-fluids must break at the right time for successful deposit of the proppant in the targeted zone and facilitate good fluid recovery and adequate wellbore clean out. The polymer degradation process by gel breakers is a function of many factors, therefore making it difficult to predict the break tim e of gravel packing and hydraulic fracturing fluids. Consequently, so much time is usually spent to conduct laboratory experiment, combine with the rigours of search through archives for similar tests for preliminary engineering simulations or for fluids design proposal. This paper therefore details a review of design criteria for gravel packing and hydraulic fracturing fluids with a view of proffering solution to production enhancemen t fluid design challenges presently encountered in the laboratory and field operations.