Proppant Selection The Key to Successful Fracture Stimulation
C.T. Montgomery & R.E. Steanson, Dowell Division of Dow Chemical U.S.A.
There are many types of proppants and mesh sizes to consider in the design of a fracture stimulation treatment. When considering proppants, sand (Ottawa, Texas Mining, Unisil), bauxite, intermediate strength proppants (ISP), resin-coated sand (RCS), precured resin-coated sand (PRCS) and Z-prop, the principal questions seem to be, "Which one do I select and how should I use it?" Maximizing adequate long-term productivity in low-permeability reservoirs is dependent on both fracture penetration and fracture, conductivity. How to obtain deeply penetrating fractures, contained and adjacent to the porous interval, is one of the problems that challenges the industry. The other is how to obtain sufficient fracture conductivity to effectively utilize the deep penetration. This paper discusses how to determine and obtain sufficient fracture conductivity. Fracture conductivity is a function of the proppant properties (i.e., strength, roundness, fines content, etc.), closure stress, drawdown rate, formation properties (i.e., proppant embedment conditions) and resultant propped fracture width. The engineering principles involved in the selection of the proper type and amount of proppant are supported with a case history. This is a "state-of-the-art" paper, attempting to bring the current technology on proppants together in one place.