Introducing OXAND. ~ 850 projects > 1,250bn OF CAPEX CAPITALISED IN SIMEO TM

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1 Introducing OXAND Independent international engineering consultancy firm specialised in industrial life cycle asset management 5 Business Units (Europe, North America), +120 consultants to support investors, owners and managers to make the right decisions ~ 850 projects > 1,250bn OF CAPEX CAPITALISED IN SIMEO TM Advanced skills and expertise in ageing, risk and financial modelling to support decision making OIL & GAS NUCLEAR LARGE ASSETS (Hydro, Roads, Railways, Ports, Real estate...) 2015 Oxand 1

2 SIMEO WellCem: Help for Decision-Making OXAND provides STATOIL with a dedicated IT Tool supporting its decision-making process for the assessment of primary cement jobs Field Operation Team Cement Log Cement Team Cased Hole Logging Team Log Analysis Well Integrity Team L Norsok L Good cement Go < L Norsok Extended Verification Decision Making Tool Dispensation Request Technical Support Decision Making Support Go / No Go 2015 Oxand 2

3 Main assumptions: Numerical 1D model 1-phase model (gas or liquid) Darcy s Law Compressible newtonian fluid, laminar flow, steady state Unidirectional flow along the well Boundary conditions at the top and bottom: Equation of the mass flow rate Q m,α for phase α: Synthetic representation of the well given each input data 2015 Oxand 3

4 Numerical 1D model Main assumptions: 2-phase model Same as 1-phase model plus: No interaction between fluids Continuity of the wetting fluid phase Intrinsic permeability of the cement is independent of the fluid Boundary conditions at the top and bottom: Wetting phase equations (a) Non Wetting phase equations (b) Equilibrium equation (c) Equation of the mass flow rate Q m,nw for the non-wetting phase (gas) : 2015 Oxand 4

5 Numerical 1D model Gaz mass flow rate calculation Input parameters Cemented annulus Name Label P TOC Q m Well parameters Length of cement L Intrinsic Cement Permeability k cem Intrinsic Defect Permeability k cem * L 2 (Length 2 nd barrier) such as L 2 = LGC - L 1 Pressure at top of cemented annular Pressure at bottom of cemented annular Depth at top of cemented annular Depth at bottom of cemented annular Inclination borehole Temperature Properties fluids Viscosity Density P bot P top z top z bot θ b T(z) µ(t,p) ρ(t,p) LGC P RES L 1 (Length 1 st barrier) such as Q(L 1 ) = Q Base Case 2015 Oxand 5

6 Base Case Mass Flow Rate Base Case: well following Norsok s requirements under severe conditions (HPHT) Characteristics and units HPHT Case study Inner diameter (m) Outer diameter (m) Cement length (mmd) 30 Well Deviation ( ) 55 TOC position (mtvd) 4370 Temperature at TOC ( C) 170 Reservoir Pressure (at top of the reservoir) (bar) Reservoir Temperature (at top of the reservoir) ( C) Fluid type Methane Cement permeability (µd) 0.1 Synthetic representation of the well with the required parameters by constitutive component Upper Acceptable Gas Mass Flow Rate (Threshold) 2015 Oxand 6

7 Simulation of different scenario Different scenario can be simulated: " Cond. 450, /8" Csg /8" Csg. 1487,5 (All depths m TVD) ΔP = 25 & 51 Bar P top = 110 Bar P bot = 135 Bar & 161 Bar TOL 1454, /4" x 9 5/8" Liner 1600,5 Wellhea d 364,81 Scenario with current and long terms reservoir pressures ITEM VALUE / RANGE UNIT Z top mtvd L good_cement mmd z bottom Function to L good_cement mtvd Inclination 60 T top 44 C T bottom 63 C P top 110 Bar P bottom Bar Cement permeability [0.1-10] GC µd Ø OuterDiameter 17 1/ m Ø InnerDiameter 13 3/ m Phase 1 : Gas Methane Nature Phase 2: Liquid Water Nature 2015 Oxand 7

8 Results from simulations Assessment of a required length of good cement to ensure a given mass flow rate: K = 0.1 µd K = 0.5 µd K = 5.0 µd 2015 Oxand 8

9 Results from simulations Example of a low pressure well: 7,00 Scenario A ; ztoc = m ; P = 25 Bar Gas mass ηuac flow rate [kg/year] 6,00 5,00 4,00 3,00 2,00 1,00 Cement Prop. = 0.1 µd Cement Prop. = 0.5 µd Cement Prop. = 5.00 µd Cement Prop. = 8.75 µd Cement Prop. = µd 0, Length of good cement [m] 2015 Oxand 9

10 Simeo WELLCEM Workflow Mass flow simulation Well geometry Boundary conditions (pressure, temperature) Reference flow rate Cement properties FLOW RATE CALCULATION 1 2 Support for dispensation request Support during cement investigations planning phase 1 st barrier and 2 nd barrier identification and caracterization (length, flow rate) Minimal required length of good cement Sensitivity analyses on well characteristics 2015 Oxand 10

11 Screenshots Full-web tool 2015 Oxand 11

12 Screenshots Automatic generation of reports 2015 Oxand 12

13 Conclusion Extended Evaluation of Primary Cement Jobs: a value-added approach Objectivity Systematic approach Quantitative and objective indicators for decisionmaking support Time and cost saving Time for decision-making reduction Elements to justify the relevance of any additional action Knowledge improvement Well portfolio regarding the cement integrity One common platform for the operational teams Increased confidence in the cement integrity assessment 2015 Oxand 13

14 Takk. Contact : Bruno CAPRA Tel.: +33 (0) bruno.capra@oxand.com 2015 Oxand 14 14