Developments in Fluids to Reduce Potential Damage from Fracturing Treatments
Authors: Tiner R.L. , Stahl E.J. , Malone W.T. 
Published: December 2007

This paper was prepared for the Society of Petroleum Engineers of AIME Symposium on Formation Damage Control, to be held in New Orleans, La., Feb. 7–8, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
A major concern to the petroleum industry has been the potential damage to the reservoir and propped fracture system following a stimulation treatment. Possible damage due to the stimulation Possible damage due to the stimulation fluid can exist from residue, fluid retention, or formation-fluid incompatibility. During recent years, a major emphasis has been placed on the development of fluid systems to minimize these possible sources of damage.
By utilizing low-residue gelling agents, potential damage to both the fracture flow capacity and formation permeability in the vicinity of the permeability in the vicinity of the fracture face should be reduced over that of fluids which contain insoluble residue from the broken gel. Several gelling agents utilizing a variety of base fluids have been developed which possess low residue. possess low residue. Numerous developments exist in the area of nonaqueous, high viscosity fracturing fluids. These fluids, usually high gravity hydrocarbons or alcohol, have been utilized in the stimulation of water-sensitive formations. High gravity hydrocarbons are particularly applicable to water-sensitive, oil producing reservoirs. Their advantages producing reservoirs. Their advantages are low residue, low surface tension, and compatibility with both the formation and formation fluids.
Methanol as a base fracturing fluid has met with success when used in low porosity, low permeability, gas reservoirs plagued with slow clean-up and formation damage. However, this fluid is somewhat more costly and often requires the use of specialized equipment. With the introduction of fracturing fluids based on mixtures of alcohol and water, an effective lower cost alternative is now available.
Laboratory tests with formation cores have shown that regained gas permeability is much more rapid permeability is much more rapid following injection of alcohol solutions than when water alone is the injected fluid. This is attributed to a reduction in surface tension and an increase in vapor pressure of the fluid due to the presence of alcohol. In addition, alcohol aids in protecting water-sensitive formations against clay migration and swelling.