Diverting Agents: Laboratory Study and Modeling of Resultant Zone Injectivities

Abstract

Diverting Agents: Laboratory Study and Modeling of Resultant Zone Injectivities N. Doerler; N. Doerler Dowell Schlumberger Search for other works by this author on: This Site Google Scholar L.P. Prouvost L.P. Prouvost Dowell Schlumberger Search for other works by this author on: This Site Google Scholar Paper presented at the SPE International Symposium on Oilfield Chemistry, San Antonio, Texas, February 1987. Paper Number: SPE-16250-MS https://doi.org/10.2118/16250-MS Published: February 04 1987 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Doerler, N., and L.P. Prouvost. "Diverting Agents: Laboratory Study and Modeling of Resultant Zone Injectivities." Paper presented at the SPE International Symposium on Oilfield Chemistry, San Antonio, Texas, February 1987. doi: https://doi.org/10.2118/16250-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE International Conference on Oilfield Chemistry Search Advanced Search AbstractA methodology for the design of the diversion stages of matrix acidizing jobs is presented. The resistance to flow induced by a cake of diverting agent deposited at the sandface of a single core has been measured in the lab under a large variety of conditions, representative of those encountered downhole. The experimental data are then combined with a numerical model to yield a design tool for diversion jobs, which enables to predict the flow distribution due to diverters in multi-layered formations, according to both reservoir and diverter properties. Finally, results obtained with the model are presented, to demonstrate how it can be used to optimize the volume of diverter slugs in matrix acidizing treatments.IntroductionMatrix treatments are often performed in multilayered formations which exhibit large contrasts of injectivity between the different layers. This difference in injectivity may originate either in different permeabilities or in uneven severities of damage. In these situations, the design engineer must make use of a placement technique in order to ensure a correct coverage of each zone to be treated.Mechanical techniques (packers, ball sealers ….) are not always practical or feasible. They are applicable only in cased holes and require a perfect isolation behind the casing. Hence, particulate diverting agents have been used in order to counter the natural trend of the fluid to enter mainly the zones with the highest injectivity. The mechanism by which diversion acts is to create a cake of solid particles mostly in front of higher injectivity layers, thus diverting the flow to the zones with less injectivity.Whereas mechanical techniques completely divert flow from one zone to the others, the diverting agents enable the equalization of the flow of treating fluid per unit of thickness between zones of different injectivities.The cakes of diverting agents must have a very low permeability, so that the diversion process is efficient in terms of flow redistribution and they must be easily removed after completion of the treatment.Crowe, in a pioneering work in 1971, demonstrated that oil-soluble resins perfectly meet these two requirements, and could be used as diverting agents in oil or gas wells. By injecting a slug of oil-soluble resin into parallel cores of different permeabilities, flowrates entering each core were equalized, whatever the permeability ratio. Moreover, the cakes could be easily removed by oil flowback so that the cores were not permanently damaged.P. 45^ Keywords: injection, redistribution, permeability, concentration, thickness, injectivity, reservoir, fluid dynamics, diverter slug, equation Subjects: Reservoir Fluid Dynamics, Formation Evaluation & Management, Acidizing, Flow in porous media, Well Operations, Optimization and Stimulation This content is only available via PDF. 1987. Society of Petroleum Engineers You can access this article if you purchase or spend a download.