subroutine Kick_Influx    !  is called in subroutine CirculationCodeSelect
    
        Use GeoElements_FluidModule
        USE CMudPropertiesVariables
        USE MudSystemVARIABLES
        USE Pump_VARIABLES
        use CDrillWatchVariables
        use CTanksVariables, TripTankVolume2 => TripTankVolume, TripTankDensity2 => TripTankDensity
        USE sROP_Other_Variables
        USE sROP_Variables
        Use KickVariables

   
   implicit none

   
!===========================================================WELL============================================================
!===========================================================WELL============================================================ 

            !write(*,*) 'Kick Influx'
  

!=================== Bottom Hole Kick Influx ENTRANCE(due to Kick) ===================
   
            Kick_Density= 2
            NewInflux_Density= Kick_Density
              
            
        if ( NewInfluxElementCreated==0 ) then ! new kick is pumped- (it is set to zero in sheykh subroutine after a new kick influx)
        call Op_Density%AddToFirst (NewInflux_Density)
        call Op_MudDischarged_Volume%AddToFirst (0.0d0)
        call Op_Mud_Forehead_X%AddToFirst (Xstart_OpSection(1))
        call Op_Mud_Forehead_section%AddToFirst (1)
        call Op_Mud_Backhead_X%AddToFirst (Xstart_OpSection(1))
        call Op_Mud_Backhead_section%AddToFirst (1)
        call Op_RemainedVolume_in_LastSection%AddToFirst (0.0d0)
        call Op_EmptyVolume_inBackheadLocation%AddToFirst (0.0d0)
        call Op_MudOrKick%AddToFirst (NewInfluxNumber)       ! KickNumber= NewInfluxNumber
        
         
            NewInfluxElementCreated= 1
        endif   
        

        Op_MudDischarged_Volume%Array(1)= Op_MudDischarged_Volume%Array(1)+ ((GasKickPumpFlowRate/60.0d0)*DeltaT_Mudline)    !(gal)    due to KickFlux 
        !write(*,*) 'kick volume ok=' , Op_MudDischarged_Volume%Array(1)
              


    end subroutine Kick_Influx
    
    
    
    
    
    
    
    
    
    
    
subroutine Instructor_CirculationMud_Edit    !  is called in subroutine CirculationCodeSelect 

    Use KickVariables
    Use MudSystemVARIABLES
    USE TD_DrillStemComponents
    Use CUnityInputs
    Use CUnityOutputs
    USE CKellyConnectionEnumVariables
    USE UTUBEVARS
    use sROP_Variables
    use sROP_Other_Variables
    use CDownHoleVariables
    

    implicit none
    



            
            if ( AnnDrillMud == .true. .and. (Rate_of_Penetration>0. .and. DeltaVolumeOp>0.0) ) then
                
                do imud= 1, Ann_Density%Length()
                    
                    if ( Ann_MudOrKick%Array(imud) == 0 ) then
                        Ann_Density%Array(imud)= (St_Density%Last() * AnnulusFlowRate + 141.4296E-4*Rate_of_Penetration*Diameter_of_Bit**2)/(AnnulusFlowRate+6.7995E-4*Rate_of_Penetration*Diameter_of_Bit**2)
                        Ann_CuttingMud%Array(imud)= 1
                    endif
                    
                enddo
                
            endif
            
    
            if ( AnnCirculateMud == .true. ) then
                
                do imud= 1, Ann_Density%Length()
                    
                    if ( Ann_MudOrKick%Array(imud) == 0 ) then
                        Ann_Density%Array(imud)= ActiveTankDensity
                        Ann_CuttingMud%Array(imud)= 0
                    endif
                    
                enddo
                
                do imud= 1, St_Density%Length()
                    
                        St_Density%Array(imud)= ActiveTankDensity
                    
                enddo                
                
            endif            
            



    end subroutine Instructor_CirculationMud_Edit
    
    
    
subroutine ShoeLostSub    !  is called in subroutine CirculationCodeSelect 

    Use KickVariables
    Use MudSystemVARIABLES
    USE TD_DrillStemComponents
    Use CUnityInputs
    Use CUnityOutputs
    USE CKellyConnectionEnumVariables
    USE UTUBEVARS
    use sROP_Variables
    use sROP_Other_Variables
    use CDownHoleVariables
    use CShoeVariables
    USE PressureDisplayVARIABLES
    Use CWarningsVariables
    

    implicit none   
    
            ShoeLost= .false.
            Kickexpansion_DueToMudLost= .false.
            
            ShoeMudPressure= PressureGauges(5)
            
            
            UGBOSuccessionCounter = UGBOSuccessionCounter + 1
            !write(*,*) 'check point 1'
            
            if (InactiveFracture == .FALSE. .AND. ((ShoeMudPressure >= FormationLostPressure) .or. ShoeFractured )) then
            !write(*,*) 'check point 2 ,UGBOSuccessionCounter' , UGBOSuccessionCounter
              
                ! if ShoeFractured changed to true , then time counter is not needed more
                    if ( UGBOSuccessionCounter /= UGBOSuccessionCounterOld+1 .and. ShoeFractured==.false. ) then
                        UGBOSuccessionCounter = 0   ! also in starup
                        UGBOSuccessionCounterOld = 0   ! also in starup
                        return   
                    else
                        UGBOSuccessionCounterOld= UGBOSuccessionCounter        
                    endif

                    if ( UGBOSuccessionCounter < 10 .and. ShoeFractured==.false.) then
                        return
                    endif 
                
            !write(*,*) 'check point 3 ,UGBOSuccessionCounter' , UGBOSuccessionCounter
                
     
                
                ShoeFractured= .true.
                
                ShoeMudViscosity= MAX(ShoeMudViscosity, 12.d0)
                !write(*,*) 'ShoeMudDensity , ShoeMudViscosity' , ShoeMudDensity , ShoeMudViscosity
                ShoeLostCoef = 10.**(-8) * 1.15741d0 * 7.08d0 * 1000000.d0 * 1.d0 * ShoeMudDensity / &
                            (ShoeMudViscosity * LOG(10000.d0))
                !write(*,*) 'lost parameters 1' , ShoeMudPressure , FormationLostPressure
                Qlost = MAX( (ShoeLostCoef * (ShoeMudPressure - (FormationLostPressure/2.0))) , 0.d0 )
                if (Qlost > 0.0) then
                    ShoeLost= .true.
                else
                    ShoeLost= .false.
                endif
                
                !write(*,*) 'Qlost=' , Qlost, ShoeMudPressure, FormationLostPressure
                call Activate_UndergroundBlowout()
                
                
                do imud= 1, Ann_Mud_Forehead_X%Length()

                        IF ( ShoeLost .and. ShoeDepth < Ann_Mud_Backhead_X%Array(imud) .and. ShoeDepth >= Ann_Mud_Forehead_X%Array(imud) &
                            .and. Ann_MudOrKick%Array(imud) == 0 .and. WellHeadIsOpen == .FALSE. ) then
                
                            Kickexpansion_DueToMudLost= .true.
                            write(*,*) 'Kickexpansion_DueToMudLost'
                            
                            EXIT
 
                        ENDIF
                
     
                enddo
    

                
            endif
            
            if (UndergroundBlowout == .false.) ShoeLost= .false.    
    
    
    
    end subroutine ShoeLostSub