A Comprehensive Geochemical-Based Approach to Quantify the Scale Problems

Abstract

Oil-field scales result from changes in the physicochemical properties (pH, temperature, pressure etc.) of the produced fluids and/or due to the chemical incompatibility between waters having different compositions (e.g., formation brine and injection brine). Nevertheless, the comprehensive modeling and prediction of such phenomena remains a challenge, due to the complexity of the precipitation kinetics and chemical reaction processes that occur in the reservoir. Hence, it is the case that often reactions in the reservoir are not considered on evaluation of the scaling tendency, probably because they are difficult to measure and also, to model the calculations considerable effort and expertise is required.Since no comprehensive geochemical-based modeling has been applied in this research area, in this work, a previously developed robust, accurate, and flexible integrated tool, UTCHEM-IPhreeqc, is used to model the comprehensive geochemistry to predict scales problem for field scale applications.IPhreeqc, the United States Geological Survey geochemical tool, is able to simulate both homogeneous and heterogeneous (mineral dissolution/precipitation), irreversible, and ion-exchange reactions under non-isothermal, nonisobaric and both local-equilibrium and kinetic conditions. Through coupling of IPhreeqc with UTCHEM, The University of Texas at Austin research chemical flooding reservoir simulator, the entire geochemical capabilities of IPhreeqc can be used in a multi-dimensional and multiphase reservoir simulator for comprehensive reactive-transport modelings.In this paper, the importance of ion activities, temperature, and pressure in the reactive-transport modeling is emphasized by performing several sensitivity analyses. Oilfield scale is quantified by including the effect of dissolution or precipitation of all possible minerals (either initially present or subsequently precipitated by injecting an incompatible water) on the reservoir petrophysical properties (e.g., porosity). Three common permeability-porosity approaches (Modified Fair-Hatch, Kozeny-Carman, and Verma-Pruess models) are then implemented in the UTCHEM-IPhreeqc simulation tool to model the effect of scalings on the reservoir permeability. To show how well this integrated tool can be applied for field scale applications, a synthetic five-spot pattern is presented using several water compositions.

A Mechanistic Integrated Geochemical and Chemical Flooding Tool for Alkaline/Surfactant/Polymer Floods

“…In using IPhreeqc, charge balance and total moles of hydrogen and oxygen must be transported along with other geochemical elements present in the system Korrani et al, 2013;Korrani et al, 2014c). For ASP simulations, care must be taken to partition the charge balance and the total moles of hydrogen and oxygen among different phases.…”

“…In this paper, we enhance UTCHEM-IPhreeqc (Korrani et al, 2013;Korrani et al, 2014c) to expand capability and flexibility of the UTCHEM geochemical module to model ASP floods. In this paper, we enhance UTCHEM-IPhreeqc (Korrani et al, 2013;Korrani et al, 2014c) to expand capability and flexibility of the UTCHEM geochemical module to model ASP floods.…”

“…IPhreeqc is being widely coupled with several transport simulators to imbed an exhaustive geochemistry in different research areas (Wissmeier and Barry, 2011;Nardi et al, 2012;Huber et al, 2012;Elakneswaran and Ishida, 2012). Details on IPhreeqc and the UTCHEM-IPhreeqc computing algorithm were previously discussed (Korrani et al, 2013;Korrani et al, 2014c;Korrani et al, 2014b). Details on IPhreeqc and the UTCHEM-IPhreeqc computing algorithm were previously discussed (Korrani et al, 2013;Korrani et al, 2014c;Korrani et al, 2014b).…”

Mechanistic Modeling of Low-Salinity Waterflooding Through Coupling a Geochemical Package With a Compositional Reservoir Simulator

“…Hence, this combines the geochemical power of IPhreeqc with the important aspects of hydrocarbon flow and compositional effects to produce a robust, flexible, and accurate integrated tool capable of including the reactions needed to mechanistically model low-salinity waterflooding.Different geochemical-based approaches to modeling wettability change in sandstones (e.g., interpolation on the basis of total ionic strength and multicomponent ion exchange through surface complexation of the organometallic components) were implemented in UTCOMP-IPhreeqc, and the integrated tool is then used to match and interpret a low-salinity experiment published by Kozaki (2012) and the field trial performed by BP at the Endicott field. Although there are many low-salinity experimental results reported in the literature, publications on modeling this process are rare.…”

“…Different geochemical-based approaches to modeling wettability change in sandstones (e.g., interpolation on the basis of total ionic strength and multicomponent ion exchange through surface complexation of the organometallic components) were implemented in UTCOMP-IPhreeqc, and the integrated tool is then used to match and interpret a low-salinity experiment published by Kozaki (2012) and the field trial performed by BP at the Endicott field.…”