Upstream-downstream integrated process for the upgrading of a heavy crude oil with capture of co2 and relative plant for the embodiment thereof

Abstract

The present invention relates to an upstream-downstream integrated process for the upgrading of a heavy crude oil with the capture of CO 2 , comprising the following operative steps: a) production of a heavy crude oil from a reservoir; b) distillation of said heavy crude oil, at atmospheric pressure or under vacuum, with the separation of a distilled fraction and a hydrocarbon residue containing asphaltenes; c) solvent deasphalting of said hydrocarbon residue containing asphaltenes with the formation of a precipitate of asphaltenes and a deasphalted oil (DAO); d1) oxy-combustion of said precipitate of asphaltenes in pure oxygen with the formation of a stream of exhausted gases comprising CO 2 and water vapour; d2) as an alternative to said oxy-combustion, gasification of said precipitate of asphaltenes in pure oxygen with the formation of a stream of syngas which is subsequently transformed into a gas stream comprising CO 2 and H 2 ; e) separation of a substantially pure gaseous stream of CO 2 from said stream of exhausted gases or from said gas stream comprising CO 2 and H 2 ; f) injection of said gaseous stream of CO 2 into the subsoil in order to recover oil or gas, by displacement, from a reservoir and/or to permanently sequester said gaseous stream of CO 2 in a geological formation. The present invention also relates to a plant for the embodiment of the above integrated process.

1 . An upstream-downstream integrated process for the upgrading of a heavy crude oil with the capture of CO 2 , comprising the following operative steps:
 a. producing a heavy crude oil from a reservoir;   b. distilling said heavy crude oil, at atmospheric pressure or under vacuum, to separate a distilled fraction and a hydrocarbon residue containing asphaltenes;   c. solvent deasphalting said hydrocarbon residue containing asphaltenes to form a precipitate of asphaltenes and a deasphalted oil (DAO);   d1. oxy-combusting of said precipitate of asphaltenes in pure oxygen to form a stream of exhausted gases comprising CO 2  and water vapour;   d2. alternatively to said oxy-combustion, gasifying said precipitate of asphaltenes in pure oxygen to form a stream of syngas which is subsequently transformed into a gas stream comprising CO 2  and H 2 ;   e. separating a substantially pure gaseous stream of CO 2  from said stream of exhausted gases or from said gas stream comprising CO 2  and H 2 ;   f. injecting said gaseous stream of CO 2  into the subsoil in order to recover oil or gas, by displacement, from a reservoir and/or to permanently sequester said gaseous stream of CO 2  in a geological formation.   
     
     
         2 . The process according to  claim 1 , further comprising mixing said DAO with at least a part of said distilled fraction to form a reconstituted crude oil. 
     
     
         3 . The process according to  claim 1 , wherein said process further comprises producing power by means of the water vapour generated in the oxy-combustion step. 
     
     
         4 . The process according to  claim 1 , further comprising injecting water vapour into the subsoil for the displacement of oil from a reservoir. 
     
     
         5 . The process according to  claim 1 , wherein the water vapour produced in the oxy-combustion and gasification steps is used for EOR treatment. 
     
     
         6 . The process according to  claim 1 , wherein the power produced by the water vapour generated in the oxy-combustion phase, is used for EOR treatment. 
     
     
         7 . The process according to  claim 1 , wherein the gaseous stream of CO 2  is injected as displacing fluid into a carbon-bed methane reservoir. 
     
     
         8 . The process according to  claim 1  wherein the syngas stream is transformed into a gas stream comprising CO 2  and H 2  by means of a CO-shift reaction. 
     
     
         9 . The process according to  claim 1  wherein said solvent is a C 3 -C 6  alkane and/or mixtures thereof. 
     
     
         10 . The process according to  claim 1  wherein said gaseous stream of CO 2  is separated from said stream of exhausted gases by cooling the exhausted gas to remove the water present and, optionally, removing the inert gases present. 
     
     
         11 . The process according to  claim 1 , wherein the said gaseous stream of CO 2  is permanently sequestered in an exhausted oil or gas reservoir or in a deep reservoir of salt water. 
     
     
         12 . The process according to  claim 1 , wherein the H 2  generated in said gasification in pure oxygen of the precipitate of asphaltenes is used in refineries or in upstream-downstream integrated complexes. 
     
     
         13 . A plant for implementing the upstream-downstream integrated process for the upgrading of a heavy crude oil according to  claim 1 , comprising:
 I) a production well (PP) for producing a heavy crude oil from a reservoir;   II) a distillation unit (DF) to distil, at atmospheric pressure or under vacuum, said heavy crude oil with the separation of a distilled fraction and a hydrocarbon residue containing asphaltenes;   III). a solvent deasphaltation unit (SDA) for treating said hydrocarbon residue containing asphaltenes with the formation of a precipitate of asphaltenes and a deasphalted oil;   IVa) a combustion unit (C) for subjecting said precipitate of asphaltenes to oxy-combustion with the formation of a stream of exhausted gases comprising CO 2  and water vapour;   IVb) or, alternatively to the unit defined in IVa), a combustion unit (C) for subjecting said precipitate of asphaltenes to a gasification process in pure oxygen with the formation of a stream of syngas which can be subsequently transformed into a gas stream comprising CO 2  and H 2 ;   V) a separation unit (SC) for separating a substantially pure gaseous stream of CO 2  from said exhausted gas stream, or from said gas stream comprising CO 2  and H 2 ;   VI) an injection unit (IN) for injecting said gaseous stream of CO 2  or the vapour produced in the process by oxy-combustion, into the subsoil to recover oil or gas, by displacement, from a reservoir and/or for permanently sequestering said gaseous CO 2  stream in a geological formation.