subroutine CirculationCodeSelect    !  is called in subroutine Fluid_Flow_Solver
    
    Use KickVariables
    Use MudSystemVARIABLES
    USE TD_DrillStemComponents
    Use CUnityInputs
    Use CUnityOutputs
    USE CKellyConnectionEnumVariables
    USE UTUBEVARS
    use sROP_Variables
    USE PressureDisplayVARIABLES
    
    

    implicit none
    
    
    Integer i
    
    !NewInfluxNumber = NoGasPocket
    
    MudSystemDotFlow_timeCounter= MudSystemDotFlow_timeCounter+1
    
            !if (ChokePanelStrokeResetSwitch == 1) then
            !    Flow_timeCounter= 0
            !endif     
    
    
    !write(*,*) 'Flow_timeCounter' , Flow_timeCounter
    
!===========================Shoe Lost=============================== 

           call ShoeLostSub
           
!===================================================================    
    
      
            MudSystemDotiLoc= 1 ! will be changed in KickFlux and Migration or Pump and TripIn (save OP Mud data)
            !KickMigration_2SideBit= .false.
            Call Set_FlowPipeDisconnect(.false.)
            Call Set_FlowKellyDisconnect(.false.)
  
            call ElementsCreation
            

            
            
            if (MUD(8)%Q > 0.0)     call FillingWell_By_BellNipple        ! Filling Well Through BellNipple ( Path j11 )
            !if (MUD(10)%Q > 0.0)     call FillingWell_By_Pumps        ! Filling Well Through Pumps ( Path j19 )
            
                !write(*,*) 'TD_RemoveVolume,Get_JointConnectionPossible=' , TD_RemoveVolume,Get_JointConnectionPossible()
            
            if (TD_RemoveVolume > 0.)  call DisconnectingPipe     !! .and. Get_JointConnectionPossible() == .false.) call DisconnectingPipe
            
            
            IF (KickFlux .AND. NOT(KickOffBottom)) THEN 
                call Kick_Influx
            endif
            
            
            
            
            IF ( MudSystemDotNewInfluxNumber > 0 ) THEN
                !write(*,*) 'KickOffBottom , ROP=' , KickOffBottom , Rate_of_Penetration
                call Kick_Migration
            endif
            
!   ============================ must be after migration ==============================            

       DO MudSystemDotKickNumber= MudSystemDotNewInfluxNumber-NoGasPocket+1 , MudSystemDotNewInfluxNumber
            ! FINDING NEW KICK LOCATIONS:
               MudSystemDotAnn_KickLoc= 0
               MudSystemDotOp_KickLoc= 0
               MudSystemDotChokeLine_KickLoc= 0
               
            do i = 1, Ann_MudOrKick%Length ()
                if (Ann_MudOrKick%Array(i) == MudSystemDotKickNumber) then
                    MudSystemDotAnn_KickLoc = i
                    exit
                endif
            end do

            do i = 1, Op_MudOrKick%Length ()
                if (Op_MudOrKick%Array(i) == MudSystemDotKickNumber) then
                    MudSystemDotOp_KickLoc = i
                    exit
                endif
            end do
                
            do i = 1, ChokeLine_MudOrKick%Length ()
                if (ChokeLine_MudOrKick%Array(i) == MudSystemDotKickNumber) then
                    MudSystemDotChokeLine_KickLoc = i
                    exit
                endif
            end do                
            
!   ============================ must be after migration-end ===========================            
            
        IF (ALLOCATED(GasPocketWeight%Array) .and. MudSystemDotKickNumber == MudSystemDotNewInfluxNumber .AND. NOT(KickOffBottom) .AND. WellHeadIsOpen) THEN

            cycle
            
        ELSE IF (ALLOCATED(GasPocketWeight%Array)) THEN
            
            if (((GasPocketDeltaVol%Array(MudSystemDotNewInfluxNumber - MudSystemDotKickNumber + 1) > 0.0 .AND. WellHeadIsOpen) .or. MudSystemDotKickexpansion_DueToMudLost) )   call Kick_Expansion
                
            if ((GasPocketDeltaVol%Array(MudSystemDotNewInfluxNumber - MudSystemDotKickNumber + 1) < 0.0 ) .OR. WellHeadIsOpen == .FALSE.)   CALL Kick_Contraction

        ENDIF
        
        
 ENDDO       
        
        
        
                
            MudSystemDotLostInTripOutIsDone= .false.  
            
            if( MudSystemDotDeltaVolumeOp >= 0.0 .and. Get_KellyConnection()==KELLY_CONNECTION_STRING) then    
                !write(*,*) 'DeltaVolumeOp=' , DeltaVolumeOp
                call Pump_and_TripIn
            elseif (MudSystemDotDeltaVolumeOp < 0.0) then
                ! when we have Utube and tripping out simultaneously, it uses "TripOut_and_Pump" subroutine, and then Utube code is done
                ! "Utube" and "Pump_and_TripIn" subroutines, not to be used simultaneously because "Utube" code supports trip in
                call TripOut_and_Pump
            endif
            
            WellOutletDensity= Ann_Density%Last()   !    (ppg) used in MudSystem    
            
            
            
            if (MUD(4)%Q > 0.) then          !     ( j4 > 0 )   ! THIS CIRCULATION CODE IS JUST FOR LINE J4, AND NOT NEEDED FOR LINE J18
                call ChokeLineMud
            endif
            
            
            call Choke_GasSound
            
            !WRITE(*,*) 'CIRCU-Ann_Saved_MudDischarged_Volume' , Ann_Saved_MudDischarged_Volume
            
!           ****Utube is called in Plot Subroutine****
            
            Call Instructor_CirculationMud_Edit
            
      
                
    call PlotFinalMudElements
    
    MudChecked= .true.
    MudSystemDotUtubePossibility= .true.
    

               !WRITE(*,*) '***********************************************************************' 


    
    
end subroutine CirculationCodeSelect