A New Method for Acid Stimulation Without Increasing Water Production: CaseStudies From Offshore Mexico (2006)

A New Method for Acid Stimulation without Increasing Water Production: Case Studies from Offshore Mexico Gabriel Hernandez Reza; Gabriel Hernandez Reza Petroleos Mexicanos Search for other works by this author on: This Site Google Scholar J. Eduardo Soriano; J. Eduardo Soriano Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Larry S. Eoff; Larry S. Eoff Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Eldon Dwyann Dalrymple Eldon Dwyann Dalrymple Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Paper presented at the International Oil Conference and Exhibition in Mexico, Cancun, Mexico, August 2006. Paper Number: SPE-103771-MS https://doi.org/10.2118/103771-MS Published: August 31 2006 Connected Content Related to: A New Method for Acid Stimulation Without Increasing Water Production Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Hernandez Reza, Gabriel, Soriano, J. Eduardo, Eoff, Larry S., and Eldon Dwyann Dalrymple. "A New Method for Acid Stimulation without Increasing Water Production: Case Studies from Offshore Mexico." Paper presented at the International Oil Conference and Exhibition in Mexico, Cancun, Mexico, August 2006. doi: https://doi.org/10.2118/103771-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 Oil Conference and Exhibition in Mexico Search Advanced Search AbstractSuccessful acid stimulation requires a method to distribute the acid between multiple hydrocarbon zones. Since almost all producing wells are inhomogeneous, containing sections of varying permeability, this can be a huge problem. In addition, the water saturation of the various zones plays an important role. Since acid is an aqueous fluid, it will tend to predominantly enter the zones with the highest water saturation. These water zones are also often the highest permeability zones, so acid stimulation will often result in large increases in water production. There are many negative aspects to increased water production, such as increased lifting and disposal costs, increased corrosion, etc. This paper describes the use of a new low viscosity system that inherently reduces formation permeability to water with little effect on hydrocarbon permeability, and also diverts acid from high permeability zones to lower permeability zones.This new system has been used in offshore Mexico in the Chuc, Caan, and Pol fields among others over the past year. During this time, over 30 wells have been treated with the new system. Most standard acid treatments in this field result in increased hydrocarbon and water production. The new system has resulted in increased hydrocarbon production with no increase in water production, and in some cases a decrease in water production. Details from several of these jobs will be presented showing the diversion and production results.IntroductionIn matrix-acidizing treatments, the acid tends to predominantly enter the highest-permeability layers and bypass the most damaged (lower-permeability) layers. In some cases, high-permeability layers are also predominantly water-bearing, thus acid also mainly enters those zones. In some cases, the acid may also break into a nearby water-bearing zone.In attempts to achieve uniform placement of acid across all layers, various placement techniques have been used.1 The most reliable method uses mechanical isolation devices (such as straddle packers) that allow injection into individual zones one at a time until the entire interval is treated. However, this technique is often not practical, cost-effective, or feasible. Without a packer, some type of diverting agent must be used.Typical diverting agents include ball sealers, degradable particulates, viscous fluids, and foams. Although these agents have been used successfully, all have potential disadvantages and none address the problem of increased water production that often follows acid treatments. Therefore, it would be a major advantage to have a material that could inherently decrease the formation permeability to water while also providing diversion.One method of controlling water production uses dilute polymer solutions to decrease the effective permeability to water more than to oil. These treatments may be referred to as relative permeability modifiers (RPM), disproportionate-permeability modifiers, or simply, bullhead treatments. The latter name is so called because these treatments can be bullheaded into the formation without the need for zonal isolation. RPM systems are thought to perform by adsorption onto the pore walls of the formation flow paths.2–4A previous paper has described the development of an RPM based on a hydrophobically modified, water-soluble polymer (referred to here as an associative polymer, or AP).5 This group of polymers was selected for study because their properties can be altered in ways that render them valuable for oilfield applications. Another paper has described a laboratory study of this polymer for use as an acid diverter.6 Keywords: acidizing, adsorption, Production Result, enhanced recovery, Fluid Dynamics, stimulation, flow in porous media, polymer, oil production, diverter Subjects: Reservoir Fluid Dynamics, Improved and Enhanced Recovery, Formation Evaluation & Management, Acidizing, Flow in porous media, Well Operations, Optimization and Stimulation This content is only available via PDF. 2006. Society of Petroleum Engineers You can access this article if you purchase or spend a download.