PROCESS FOR PRE-REFINING CRUDE OIL FOR THE PRODUCTION OF AT LEAST TWO NON-ASPHALTENIC OILS Pa, Pb, AND AN ASPHALTENIC OIL Pc

Abstract

A process for pre-refining a crude oil P is described in which P is fractionated into several fractions, some of which are typically hydrotreated, hydrocracked or hydroconverted, then said fractions are re-composed and at least three pre-refined oils Pa, Pb, Pc are produced, Pc being a residual asphaltenic oil and Pa and Pb being two non asphaltenic oils having different ratios R wherein: R =(0.9N+0.5VGO+)/(MD+0.1VGO+), in which: N=naphtha [30° C./170° C.]; MD=middle distillates: [170° C./260° C.] and VGO+=fraction boiling above 360° C. R translates as the relative potential of a non residual oil to be converted into gasoline with respect to middle distillates during its subsequent refining.

1 . A process for pre-refining at least one crude oil P with catalytic hydrogenating treatment of one or more cuts derived from P, comprising:
 at least one first step F 1  for initial fractionation by distillation, (PRE-DIST), to produce a first residue R 1  and at least one non-asphaltenic first stream E 1 ;   at least one second step F 2  for fractionation of at least a portion of R 1  by vacuum distillation, (VAC-DIST), and/or by solvent deasphalting (SDA), to produce at least one second non asphaltenic stream E 2  and an asphaltenic residue R 2 ;   at least one step for hydrotreatment HDT and/or hydroconversion HDC and/or hydrocracking HDK of at least a portion of E 2  to produce an effluent HE 2 ;   optionally, an RHDC step for hydroconversion of at least one asphaltenic fraction derived from R 2 ;   in which the fractionation and/or catalytic hydrogenating treatment steps of the process are determined so that at least two of the non asphaltenic effluents produced from P have different ratios R, in which:
     R =(0.9N+0.5VGO+)/(MD+0.1VGO+), in which: 
   N=naphtha: % by weight of cut boiling between 30° C. and 170° C.;   MD=middle distillates: % by weight of cut boiling above 170° C. and at most at 360° C.;   VGO+=% by weight of fraction boiling above 360° C.;   the process also comprising the following steps:   a) re-composing and producing at least two non asphaltenic oils Pa and Pb having ratios R, i.e. Ra and Rb, which are different, from non asphaltenic effluents produced from P, optionally hydrotreated and/or hydroconverted and/or hydrocracked;   b) producing at least one residual oil Pc comprising at least the major portion of the asphaltenes of the asphaltenic residue R 2  or at least residual asphaltenes after RHDC hydroconversion if the process comprises said step,   and in which Pa, Pb and Pc are three oils, final products from pre-refining process, each of said oils being intended for use as an initial distillation feedstock for one or several oil refineries, and each of said oils comprises at least 6% by weight of naphtha N, at least 10% by weight of middle distillates MD and at least 10% by weight of vacuum distillate VGO.   
   
   
       2 . A process according to  claim 1 , in which Pa and Pb are essentially formed from fractions derived from the following group of cuts derived from P, optionally hydrotreated and/or hydroconverted and/or hydrocracked: naphtha N, middle distillates MD, intermediate gas oil IGO, light LVGO, heavy HVGO or total VGO vacuum distillate, and deasphalted oil DAO. 
   
   
       3 . A process according to  claim 1 , in which 1.15<Ra/Rb<4. 
   
   
       4 . A process according to  claim 1 , in which 0.8<Ra<1.7 and 0.3<Rb<1.0. 
   
   
       5 . A process according to  claim 1 , in which Pc comprises at least the major portion of the effluent from ebullated bed hydroconversion, RHDC, of R 2 . 
   
   
       6 . A process according to  claim 1 , in which R 2  is asphalt AS obtained by solvent deasphalting SDA. 
   
   
       7 . A process according to  claim 6 , in which AS is hydroconverted in an ebullated bed, supplemented with a liquid diluent comprising at least 30% by weight of compounds boiling below 340° C. 
   
   
       8 . A process according to  claim 7 , in which the quantity of diluent is in the range 4% to 40% by weight of AS. 
   
   
       9 . A process according to  claim 6 , in which the untreated asphalt AS is directly mixed with one or more oil fractions to form the oil Pc, the vacuum residue of which then contains an increased quantity of virgin asphaltenes compared with the vacuum residue of oil P. 
   
   
       10 . A process according to  claim 9 , in which said oil fractions comprise at least one crude oil fraction P which is mixed with AS. 
   
   
       11 . A process according to  claim 1 , in which Pa, Pb and Pc are formed so that the percentage of compounds boiling between 360° C. and 400° C. with respect to the VGO fraction is lower for Pb than for P, and likewise for at least one of oils Pa, Pc. 
   
   
       12 . (canceled) 
   
   
       13 . A process according to  claim 1 , in which at least the major portion of Pa and Pc is transported via pipelines and oil tankers for use as an initial distillation feed for one or typically several oil refineries. 
   
   
       14 . (canceled)