Well-History-Based Prediction of Injectivity Decline During Seawater Flooding

Abstract

Well-History-Based Prediction of Injectivity Decline during Seawater Flooding Pavel G. Bedrikovetsky; Pavel G. Bedrikovetsky Norte Fluminense State U. Search for other works by this author on: This Site Google Scholar Marcos Jose Da Silva; Marcos Jose Da Silva Search for other works by this author on: This Site Google Scholar Diogo Rocha Fonseca; Diogo Rocha Fonseca Search for other works by this author on: This Site Google Scholar Maylton Freitas Da Silva; Maylton Freitas Da Silva Petrobras Search for other works by this author on: This Site Google Scholar Alexandre Guedes Siqueira; Alexandre Guedes Siqueira Search for other works by this author on: This Site Google Scholar Antonio Luiz de Souza; Antonio Luiz de Souza Search for other works by this author on: This Site Google Scholar Claudio Jose Alves Furtado Claudio Jose Alves Furtado Petrobras Cenpes 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-93886-MS https://doi.org/10.2118/93886-MS Published: May 25 2005 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Bedrikovetsky, Pavel G., Da Silva, Marcos Jose, Rocha Fonseca, Diogo, Da Silva, Maylton Freitas, Siqueira, Alexandre Guedes, de Souza, Antonio Luiz, and Claudio Jose Alves Furtado. "Well-History-Based Prediction of Injectivity Decline during Seawater Flooding." Paper presented at the SPE European Formation Damage Conference, Sheveningen, The Netherlands, May 2005. doi: https://doi.org/10.2118/93886-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search 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 AbstractDrastic loss of injectivity during waterflood using sea/produced water has been reported worldwide. It happens due to capture of solid and liquid particles from the injected water by the rock resulting in permeability decline, and also due to formation of low permeability cake on the wellbore. Both factors result in injectivity impairment.Reliable prediction of injectivity decline should be based on mathematical modelling using coefficients that are well known for a specific well/field.The mathematical model for injectivity damage contains four parameters: filtration and formation damage coefficients, critical porosity ratio and filter cake permeability. Nevertheless, just three constants can be extracted from two-piece-wise-linear injectivity decline curve.In the current paper we propose the correlation between the formation damage coefficient and the critical porosity fraction to be used as a fourth equation allowing for characterization of injectivity damage system.Eighteen well data have been treated, and values for four parameters of injectivity damage have been calculated. The obtained values have the same order of magnitude as those obtained from laboratory corefloods. It validates the proposal to use the correlation between the formation damage coefficient and the critical porosity fraction for characterisation of injectivity damage system from well history for the purpose of further prediction of well injectivity.IntroductionInjectivity decline during waterflooding by sea/produced water has been widely reported in the literature[1,2]. The reports describe numerous cases from North Sea, Gulf of Mexico, Persian Gulf, and Campos Basin. The phenomenon is explained by capture of solid and liquid particles from the injected water by the rock, resulting in permeability decline, and also due to formation of low permeable external filter cake on the wellbore. Both phenomena result in injectivity decline during waterflooding.Reliable prediction of injectivity decline from a well injectivity index history would allow planning of injected water treatment and well stimulation procedures and is, therefore, an important problem of formation damage theory. The reliable prediction of injector behaviour should be based on mathematical modelling using parameters that are to be well known for a specific well/field.The problem of characterisation of formation damage system from well injectivity history has been discussed in the literature with regards to well behaviour prediction and decision-making on possible well stimulation[3–5]. The formation damage system is characterised by four parameters: filtration and formation damage coefficients, critical porosity fraction and filter cake permeability. Nevertheless, just three constants can be extracted from the two-piece-wise-linear well injectivity decline curve: impedance slope during deep bed filtration, transition time and impedance slope during external cake formation. So, one equation is missing.One way to overcome the problem is to assume aposteriori the fixed value for the critical porosity fraction[5,6].A correlation between the formation damage coefficient and the critical porosity fraction has been derived in a previous work[7] based on the analysis of several laboratory tests on coreflood by poor quality water[8–11].In the current paper, we assume this correlation to be valid for reservoir conditions also, and use it as an additional equation for characterising the formation damage system.The data of eighteen wells from eleven different oilfields have been treated, and values for four parameters of formation damage have been calculated. The obtained values for formation damage parameters have the same order of magnitude as those obtained from laboratory corefloods. It allows proposing a method for complete characterisation of injectivity damage system from well history for the purpose of further prediction of well injectivity. Keywords: prediction, porosity fraction, critical porosity fraction, transition time, correlation, pressure drop, filtration coefficient, injectivity decline, injection, permeability Subjects: Improved and Enhanced Recovery, Waterflooding This content is only available via PDF. 2005. Society of Petroleum Engineers You can access this article if you purchase or spend a download.