Mineralogy Driven Scale Inhibitor Squeeze Designs (2005)

Mineralogy Driven Scale Inhibitor Squeeze Designs Rick David Gdanski; Rick David Gdanski Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Gary P. Funkhouser Gary P. Funkhouser Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Paper presented at the SPE European Formation Damage Conference, Sheveningen, The Netherlands, May 2005. Paper Number: SPE-94510-MS https://doi.org/10.2118/94510-MS Published: May 25 2005 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Gdanski, Rick David, and Gary P. Funkhouser. "Mineralogy Driven Scale Inhibitor Squeeze Designs." Paper presented at the SPE European Formation Damage Conference, Sheveningen, The Netherlands, May 2005. doi: https://doi.org/10.2118/94510-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 European Formation Damage Conference and Exhibition Search Advanced Search AbstractThis paper will discuss several aspects of how formation mineralogy can affect treatment designs. The paper will show how the mineralogy can be used to create a first good estimate of the adsorption isotherm, which is normally the primary controlling mathematical function that describes how the scale inhibitor will return from the formation. This was accomplished by first determining the true equilibrium adsorption isotherms of an example scale inhibitor on various single minerals. Short-core tests are often used to determine whether issues of formation damage might be relevant. However, this paper will show that scale inhibitors, particularly at pH less than 5, are reactive with formation mineralogy and can lead to fluid conditions not achievable in short-core testing, and therefore not generally anticipated during the squeeze treatment. Consequently, short-core tests may not always be a reliable indication of damage potential. This paper will discuss how an evaluation of the formation mineralogy can lead to insight into ways to avoid many damage mechanisms unobservable in short-core testing.IntroductionPrevention of formation damage caused by scaling brines is a common challenge for producing wells. Deposits that can occur in the formation and in the tubulars are often mitigated with scale inhibitors by squeezing them into the formation. One might expect that there would be an optimum "normalized" squeeze design that would be applicable for nearly all formations, perhaps based on daily water production rates, for example. However, this is not the case. Squeeze designs that work very efficiently at preventing scale in one area may not provide the same normalized performance in another area. The squeeze treatments themselves must also not damage the formation. Unfortunately, squeeze treatments that show no damaging effects in one formation may show extensive loss of production in another.Previous work has demonstrated the concept of measuring adsorption isotherms of a scale inhibitor on specific surfaces using a static adsorption procedure. The goal of this method is to identify the true equilibrium adsorption isotherm. Once available, deviations from this isotherm may indicate the presence of kinetic processes or chemical reactions.Isotherms on Specific MineralsA series of adsorption isotherms for the common scale inhibitor diethylenetriamine pentamethylenephosphonic acid (DETPMP) on specific mineral surfaces were determined using a static adsorption procedure previously reported.[1] The various minerals were obtained as either a powder or chunks. Chunks were ground to a fine powder. All minerals were analyzed for BET surface area. The brine for the adsorption studies was simple 6% NaCl brine without other ions such as calcium or magnesium. Adsorption tests were all conducted at 85ºF.The experimental data and least squares regression isotherms for DETPMP adsorbing on some of the specific minerals at near-neutral pH are reported in Figs. 1 to 4. The figures and regressions were produced with semi-log plots so that the quality of fit could be more readily seen. In fact, fitting the data without the use of the semi-log presentation initially led to incorrect fits as the errors were not visible with the typical linear axes plots. The Langmuir isotherm (Eq. 1) was used to fit these experiments, though the modified Langmuir equation (Eq. 2) was used to fit the smectite adsorption data and many of the pH 3 experiments. The modified Langmuir isotherm includes an additional lateral interaction parameter, ß.[2] Notice that when ß is 0, the modified Langmuir becomes the classical Langmuir equation. Keywords: spe 94510, scale inhibitor, wax remediation, concentration, asphaltene inhibition, acidizing, adsorption, downhole intervention, oilfield chemistry, hydrate remediation Subjects: Production Chemistry, Metallurgy and Biology, Acidizing, Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene, Well Intervention, Well Operations, Optimization and Stimulation This content is only available via PDF. 2005. Society of Petroleum Engineers You can access this article if you purchase or spend a download.