New Diverting Techniques for Acidizing and Fracturing

Abstract

This paper was prepared for the 40th Annual California Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in San Francisco, Calif., Nov. 6–7, 1969. 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 OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal 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 Diverting materials and techniques are discussed in this paper from the standpoint of laboratory evaluation, field application and job results. A brief review is given on the conventional materials used for fluid diversion. These include naphthalene, rock salt, paraformaldehyde and a wax-polymer. paraformaldehyde and a wax-polymer. A more detailed discussion is presented on a new solid diverting agent that is completely soluble in both water and oil. Laboratory and field data indicate that this material, due to its high degree of thermal stability and solubility properties can be applied in a larger number properties can be applied in a larger number of wells than the solids mentioned previously. Foam has demonstrated the ability to be used as a fluid diverter in many wells where other diverting systems are ineffective. Properties of foam are discussed along with unique field applications and results of jobs utilizing the foam diverting system. Introduction When stimulating a formation, it is of considerable importance that the treating fluid be distributed into each interval of production or injection. Quite often the formation of interest contains at least one section with permeability that is markedly different from permeability that is markedly different from the remaining sections; or the formation is comprised of a series of zones, each differing from the other in reservoir pressure as well as permeability. For these reasons, some method of fluid diversion is necessary to obtain maximum stimulation from any of the various types of pressure treatments. Many techniques and materials have been utilized in attempting to control the placement of fluids into the formation. These include mechanical devices such as bridge plugs, packers and perforation ball sealers. packers and perforation ball sealers. Combinations of bridge plugs and packers have been used successfully in many areas; however, their use is limited to cased holes and they are expensive to use. Likewise, perforation ball sealers can be applied only perforation ball sealers can be applied only in wells completed with casing. They often necessitate high pump rate, and the optimum number for a given job is difficult to determine. Another method of fluid injection utilizes pressure build-up across perforations, due pressure build-up across perforations, due to the velocity of fluid in the perforations, to break down additional sections of a formation.