NETool TM a toolbox for Improved Reservoir Management Terje Rudshaug, DPT AS Thormod Johansen, Memorial University Dave Smith, DPT US, Inc Arve Huse, DPT AS FORCE AWTC Seminar, April, 2004 Advanced Wells - Lessons Learned (application experience) and Future Directions/Opportunities

NETool TM What is NETool™?  is a fast, steady-state, network based simulator  is modelling fluid flow:  through the near wellbore region  into any type of well configuration  through any type of well completion  is modelling reservoir flow via upscaled permeabilities and PI models  is modelling wellbore hydraulics in completions:  using completion specific flow correlations  handling simultaneous tubing and annulus flow – also bi-directional  having automatic solving of flow directions  is using a Black-Oil PVT formulation  can be used standalone or coupled with a reservoir simulator  is filling the gap between conventional reservoir simulators and well hydraulics software

NETool TM is a planning and decision making tool which can be used in: What is NETool™?  optimization of well design, well placements, well completions and well intervention programs  quick diagnostics or “what if” analysis during drilling, production and well interventions  “Smart Field” realtime production and injection control in combination with “smart” well technology

Annulus Well Completion  P f1  P f2  P an = P f1 + P f2    p S  p S  p =  p f +  p a NETool™ - Principles Reservoir simulator NETool TM model Formation  The well completion and the near wellbore region are represented by a network of nodes that can be interconnected by flow channels.  The flow is locally one-dimensional i.e. the flow between two adjacent nodes is averaged over the cross section of the physical flow path.

NETool™ - Principles  The network geometry is sufficiently general to allow simulation of any completion type, however, simple enough to provide high computational efficiency.

NETool™ - Reservoir flow modelling  Upscaling permeability data:  Anisotropy handled by transform to an equivalent isotropic system  Sampling of isotropic permeability data around wellbore segments

PI models:  Radial flow for vertical sections  Steady State  Pseudo Steady State with Shape Factors  Horizontal Models for horizontal sections  Steady State – Joshi model  Pseudo Steady State – Babu & Odeh model  Modelling of skin  Damage zone skin (handled in PI equation)  Perforation skin (explicit calculation)  Karakas & Tariq  Furui, Zhu & Hill (incl perf orientation) NETool™ - Reservoir flow modelling

 Horizontal well with Open Hole completion – Including damage zone NETool™ - Completion Modeling

 Horizontal well with Cemented and Perforated Liner – including damage zone and 2 skin models

NETool™ - Completion Modeling  Completions with Open Annulus:  Blank Pipe  Slotted Liner  Wire-wrapped screens  Inflow Control Devices (ICDs)  Option for Collapsed Annulus  Gravel Packs:  Open hole  Cased hole

NETool™ - Completion Modeling  Completions with Open Annulus:  Blank Pipe  Slotted Liner  Wire-wrapped screens  Inflow Control Devices (ICDs)  Option for Collapsed Annulus  Gravel Packs:  Open hole  Cased hole

NETool™ - DIACS well design

NETool™ - Completion Modeling  Multilateral well with sections of Inflow Control and Zonal isolation

NETool™ - User interface

NETool™ Ex 1: IOR on the Troll Field Courtesy Hydro, 2004 NETool TM used for design of inflow control to reduce coning and increase oil recovery  Development of thin oil rims through use of advanced well technology

 Horizontal well without Inflow Control Device NETool™ Ex 2: Use of Inflow Control

 Horizontal well with Inflow Control Device NETool™ Ex 2: Use of Inflow Control

Simulations performed at same total reservoir volume from well NETool™ Ex 2: Inflow Profile Comparisons

Simulations performed at same total reservoir volume from well NETool™ Ex 2: Results from coupling with Eclipse

NETool™ Ex 3: Dual lateral Producer

NETool™ Ex 3: 3 yrs - Lateral with screens only

NETool™ Ex 3: 3 yrs - Lateral with stinger

NETool™ Ex 3: Log Data vs Simulator Data

NETool™ Ex 3: Final Completion Run

Moving Nodes Annular Flow Liner-CT pFpF Annular Flow Liner/Formation psps pFpF Annular Flow Liner-CT Pipe Flow pFpF psps psps NETool™ Ex 4: PLT Interpretation

Reservoir Drilling NETool Initial Reservoir Simulations Well Location Well Length Hole Size Rough Completion Drilling Feasibility Drillable Well Hole Size Completeable Well Data Communication Refined Simulations Coupled Simulations Drilling and Completion Program Design Drill and Log Final Completion Design (Realtime Sims) Complete Well Log Data Refined Completion Profiles NETool™ - Multidisciplinary Work Process

NETool™ - Current developments  NETool Version 2.0 – mid 2004  Beggs & Brill Multi-phase tubing and annular flow model  Ability to use OLGAS2000 from Scandpower for modeling multi-phase flow in tubing and annulus  Cased hole Gravel Pack  Tabular input option  User friendly log data import  NETool.dll Version 1.0 – mid 2004  Allows easier coupling to other simulators

NETool™ - R&D R&D at Memorial University under Dr. T.Johansen:  Stream-tube based pre-processor for IPR Upscaling  Experimental research in Multi-Phase flow rig:  Flow in annulus with radial inflow and varying pipe roughness  Modeling slip phenomena in well flow  Modeling of Transient well flow phenomena:  Transient well test analysis in advanced wells  Water blocking  Well clean up  Gravel packing  Modeling of Compositional well flow phenomena for Prediction of Solids Precipitation in Well Completions  Combining Stochastic Reservoir modeling, Stream-tube modelling and Well Flow modeling:  Simulation while drilling  Risked based decision making

NETool™ - Summary NETool TM is a Reservoir Management Toolbox for multidisciplinary teams dealing with well planning, completion and production optimization NETool TM encourage interdisciplinary interaction and decision processes and ensures that all expertise and experience is involved to the benefit of the project NETool TM can model any well geometry and most completions currently available in the market NETool TM is under continuous development to meet the challenges of tomorrow