Wrong well head position when some legs for multilateral wells are outside of the grid - fm_well_trajectory

[slawekszklarz]

For a well that is inside the model grid the well head indexes I and J (in WELSPECS) are set to I and J of the first cell of the well (I and J from first entry of COMPDAT). In case when a well is outside of the grid, the well is reduced to a single cell and shut in the first cell of the model.

However in case of a multilateral well if the main leg is outside of the grid, then well heads for all the legs are set to the first cell, including the ones that are in the grid, example of generated .SCH files where legs Y1 (main) and Y3 are outside of the grid and Y2 is inside and yet I and J are set to 1 and 1 for Y2:

WELL_Y1.SCH

-- WELL  GROUP           BHP    PHASE  DRAIN  INFLOW  OPEN  CROSS  PVT    HYDS  FIP 
-- NAME  NAME   I    J   DEPTH  FLUID  AREA   EQUANS  SHUT  FLOW   TABLE  DENS  REGN 
WELSPECS 
   WELL GROUP     1  1  1*     WATER    0.0    STD     STOP  YES    0      SEG   0    / 
     / 
-- WELL                        OPEN   SAT   CONN           WELL      KH             SKIN      D      DIR 
-- NAME   I     J    K1   K2   SHUT   TAB   FACT           DIA       FACT           FACT      FACT   PEN 
COMPDAT 
   A4   1   1   1   1   SHUT   1*    1   1*   1   0.00000   1*     'Z' / 
  /  

WELL_Y2.SCH

-- WELL  GROUP        BHP    PHASE  DRAIN  INFLOW  OPEN  CROSS  PVT    HYDS  FIP 
-- NAME  NAME   I  J  DEPTH  FLUID  AREA   EQUANS  SHUT  FLOW   TABLE  DENS  REGN
WELSPECS
   WELL GROUP     1  1  1*     WATER    0.0    STD     STOP  YES    0      SEG   0    /
/
-- WELL                       OPEN   SAT   CONN           WELL      KH             SKIN      D      DIR
-- NAME   I    J    K1   K2   SHUT   TAB   FACT           DIA       FACT           FACT      FACT   PEN
COMPDAT
   WELL     33   50   1    1    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     33   50   2    2    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     33   50   3    3    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     34   50   3    3    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     34   50   4    4    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     34   50   5    5    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     34   50   6    6    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     35   50   6    6    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     35   50   7    7    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   wELL     35   50   8    8    OPEN   1*    1*   0.30000   1*   0.00000   1*     'Z' /
   WELL     36   50   8    8    OPEN   1*    1*   0.30000   1*   0.00000   1*     'X' /
/

WELL_Y3.SCH

-- WELL  GROUP           BHP    PHASE  DRAIN  INFLOW  OPEN  CROSS  PVT    HYDS  FIP 
-- NAME  NAME   I    J   DEPTH  FLUID  AREA   EQUANS  SHUT  FLOW   TABLE  DENS  REGN 
WELSPECS 
   WELL  GROUP     1  1  1*     WATER    0.0    STD     STOP  YES    0      SEG   0    / 
     / 
-- WELL                        OPEN   SAT   CONN           WELL      KH             SKIN      D      DIR 
-- NAME   I     J    K1   K2   SHUT   TAB   FACT           DIA       FACT           FACT      FACT   PEN 
COMPDAT 
   WELL   1   1   1   1   SHUT   1*    1   1*   1   0.00000   1*     'Z' / 
  /  

Possible solution is to set I and J in WELSPECS for WELL_Y2 to the first entry of the COMPDAT for that leg. In above example this would be 33 and 50). Or default well head with 1* and 1* which should then default to first entry in COMPDAT.