Permeability Damage Due to Asphaltene Deposition : Experimental and Modeling Aspects

Abstract

Les propriŽtŽs d'Žcoulement de plusieurs bruts asphaltŽniques ont ŽtŽ ŽtudiŽes ˆ la tempŽrature du rŽservoir d'origine dans des roches de morphologie et minŽralogie diffŽrentes.Les expŽriences rŽalisŽes mettent en Žvidence une rŽduction progressive de la permŽabilitŽ ˆ l'huile au cours de l'injection, plus ou moins rapide selon les cas. L'existence de dŽp™ts organiques a ŽtŽ vŽrifiŽe par des mesures de pyrolyse Ç Rock-Eval È effectuŽes sur des sections d'Žchan-tillons prŽlevŽes en fin d'Žcoulement ˆ diffŽrentes distances de la face d'entrŽe. Cette technique permet de quantifier le profil des dŽp™ts.L'interprŽtation des expŽriences de colmatage et leur simulation sont traitŽes en assimilant les asphalt•nes dans l'huile ˆ des particules collo•dales en suspension, susceptibles de se dŽposer ˆ la surface des pores et ainsi de rŽduire la permŽabilitŽ du milieu poreux. Les premi•res simulations ont ŽtŽ rŽalisŽes en utilisant le mod•le IFP d'endommagement particulaire Ç PARIS È, qui a ŽtŽ rŽcemment gŽnŽralisŽ au cas de dŽp™t en multicouches. On observe un accord qualitatif satisfaisant avec les rŽsultats expŽrimentaux. PERMEABILITY DAMAGE DUE TO ASPHALTENE DEPOSITION: EXPERIMENTAL AND MODELING ASPECTSThe flow properties of several asphaltenic crudes were studied at reservoir temperature in rocks of different morphology and mineralogy.The experiments performed showed a progressive reduction in permeability to oil during injection, varying in rate according to the system considered.The existence of organic deposits was verified by ÒRock-EvalÓ pyrolysis measurements made on sections of samples taken at the end of flow at different distances from the entry face. This technique enables the profile of the deposits to be quantified.The interpretation of the permeability damage experiments and their simulation are treated by comparing the asphaltenes in oil to colloidal particles in suspension, capable of being deposited at the surface of the pores and thus reducing the permeability of the porous medium. The first simulations were carried out using the ÒPARISÓ IFP particle damage model, which has recently been Se ha procedido al estudio de las propiedades de circulaci-n de varios crudos asfaltŽnicos a la temperatura del yacimiento de origen en rocas de morfolog'a y mineralog'a de distinta 'ndole.Las experimentaciones llevadas a cabo hacen resaltar una reducci-n progresiva de la permeabilidad al petr-leo durante el transcurso de la inyecci-n, m ‡s o menos r ‡pida segoen los casos.La existencia de sedimentos org ‡nicos se ha verificado mediante mediciones de pir-lisis "Rock-Eval" efectuadas mediante secciones de muestras extra'das al final de la circulaci-n fluida y a distintas distancias de la cara de entrada. Esta tŽcnica permite cuantificar el perfil de las sedimentaciones La interpretaci-n de las experimentaciones de entarquinamiento (obstrucciones) y su simulaci-n se tratan asimilando los asfaltenos en el petr-leo a part'culas coloidales en suspensi-n, susceptibles de depositarse en la superficie de los poros y, por ende, r...

Causes of Formation Damage and Guidelines for Remadial Treatment for Western Sirte Bain Libyan Carbonate Oil Reservoirs

“…These interbedded clays can be dislodged and migrate upon the reduction of the confining pressure holding them together with the reservoir rock grains. The migration of these fines, as it was stated before, was responsible for some of the formation damage evidenced in these fields 8,9 . 3.…”

Experimental Study and Mathematical Modeling of Asphaltene Deposition Mechanism in Core Samples

“…In order to verify the accuracy of the proposed asphaltene deposition model, the model was run using the data given by Minssieux et al [10], as denoted GF3. Figures 36 to 40 compare the results of the pressure drop, deposited asphaltene in the porous rock, remaining asphaltene concentration in the flowing oil, and permeability and porosity profiles at various times using the proposed model with those obtained from the Wang and Civan [7] model and the model based on the monolayer adsorption equilibrium mechanism.…”

“…Asphaltene precipitation and deposition are two different processes and are governed by different mechanisms. The asphaltene deposition is governed by four mechanisms; surface deposition, entrainment, plugging and adsorption (surface excess or Langmuir theory) [6][7][8][9][10][11][12]. When precipitation occurs, asphaltene particles are aggregated and a new solid phase is generated in the oil flow, whereas when deposition takes place on the rock, this can change the wettability of the reservoir formation and reduce oil production [13].…”

The Colloidal Approach. A Promising Route for Asphaltene Deposition Modelling

“…This could happen when hydrodynamic forces counterbalance exactly the maximum adhesion forces. If this critical shear rate could not be achieved in the system, a progressive bridging will occur, provoking the progressive plugging of the porous medium [12,13,24].…”