How to find field candidates for enhanced
How to find field candidates for enhanced recovery by water additives on the NCS Enhanced Recovery by water additives FORCE Seminar 08. 02. 2007 Jan Bygdevoll, Principal Engineer, NPD Why is a field a candidate for enhanced recovery ? Because there is more oil to potentially be recovered than by methods applied today What is a method for enhanced recovery ? Anything that increase (or enhance) the recovery of oil (or gas) from a field Injection methods Water Gas, including CO2 Combination (WAG) Additives to injected water Surfactants Polymers Other ? 08.02.07 2 Norwegian Oil production RNB2006 Oljeproduksjon, Norsk kontinentalsokkel Alle ressurskategorier Uoppdagede ressurser Ressurser i funn Ressurser i felt Reserver Faktisk 200 180 160 Produsert per 31.12.2005: 3,0 GSm3 Gjenværende reserver: 1,2 GSm3 Ressurser i felt: 0,4 GSm3 Ressurser i funn: 0,1 GSm3 Uoppdagede ressurser: 1,2 GSm3 140 MSm3 120 100 80 60 40 20 0 1970 1980 1990 2000 2010 2020 2030 M:\ La g\ D-Re ssAna lyse \ EKM\ Tot a lprod.xls 08.02.07 3 Oil production – prognosis to 2011 (RNB 2007) 200 Ressurser i funn/Resources in discoveries Ressurser i felt/Resources in fields Reserver/Reserves 3.0 Historisk produksjon/Actual production 2.0 100 millioner fat per dag million barrels per day millioner Sm³ 3 million Sm 150 1.0 50 0 0.0 1995 08.02.07 1997 1999 2001 2003 2005 2007 2009 2011 4 Oil profiles for Norwegian fields 200 180 160 Rest 140 Balder Norne 120 MSm3 Ula Draugen 100 Heidrun 80 Oseberg Grane Troll Grane 60 Valhall Gullfaks Snorre Eldfisk 40 Statfjord 20 Ekofisk 0 1980 08.02.07 1985 1990 1995 2000 2005 2010 2015 2020 2025 5 Status for NPD’s goal on Reserve Growth for Oil 2005 – 2015 800 G o a l fo r re s e rve g ro w th P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th to ta l 700 P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th in e x is tin g fie ld s C u m u la tive re s e rve g ro w th in to ta l 600 C u m u la tive re s e rve g ro w th fro m e x is tin g fie ld s Mill Sm3 500 400 300 200 100 0 2 0 04 08.02.07 20 0 5 2006 2 0 07 2 00 8 2009 2 01 0 20 1 1 20 1 2 2 0 13 20 1 4 6 Status for NPD’s goal on Reserve Growth for Oil 2005 – 2015 G o a l fo r re s e rve g ro w th P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th to ta l 800 P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th in e x is tin g fie ld s C u m u la tive re s e rve g ro w th in to ta l C u m u la tive re s e rve g ro w th fro m e x is tin g fie ld s 700 R N B 2 0 0 6 O p e ra to rs p ro g n o s is R N B 2 0 0 7 O p e ra to rs p ro g n o s is 600 Mill Sm3 500 400 300 200 100 0 2004 08.02.07 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 7 08.02.07 Troll I Gullfaks Oseberg Statfjord Heidrun Snorre Valhall Eldfisk Hod Åsgard Tordis Gyda Alvheim Vigdis Veslefrikk Visund Norne Oseberg Øst Snøhvit Draugen Ula Kristin Balder Brage Vest Ekofisk Grane Njord Gullfaks Sør Tor Oseberg Sør -200 Troll II Ekofisk MSm³ Produced, yet to produce and oil remaining in ground based on current plans 600 400 200 0 -400 Remaining oil in ground at planned cessation Produced oil end 2006 Remaining oil reserves -600 8 Produced, yet to produce and oil remaining in ground based on current plans 600 400 MSm³ 200 0 -200 Chalk reservoir Sand reservoir w/ water inj Sand reservoir w/ gas inj -400 Remaining oil in ground at planned cessation Produced oil end 2006 Remaining oil reserves -600 08.02.07 9 Produced, yet to produce and oil remaining in ground based on current plans 120 100 80 60 40 MSm³ 20 Volve Urd Mime Tambar Glitne Jotun Tyrihans Yme Varg Kvitebjørn Statfjord Øst Albuskjell Frøy Embla Fram Hod Åsgard Tordis Gyda Alvheim Vigdis Veslefrikk Visund Norne Statfjord Nord -40 Oseberg Øst -20 Snøhvit 0 -60 Remaining oil in ground at planned cessation Produced oil end 2006 Remaining oil reserves -80 -100 08.02.07 10 Development in recovery factor grouped by field seize Recovery Factor Oil (%) 60 50 40 30 NB! The number of fields varies with time 20 1992 08.02.07 1993 1994 1995 1996 1997 1998 1999 <15 million Sm3 oil > 50 million Sm3 oil 15 - 50 million Sm3 oil Average all fields 2000 2001 2002 2003 2004 2005 2006 11 Recovery factor versus Reservoir Complexity Index (RCI) – a tool for estimating potential ? 0.70 y = -0.776x + 0.7779 2 R = 0.8095 0.60 0.50 Utv grad 0.40 0.30 0.20 0.10 0.00 0.10 08.02.07 0.20 0.30 0.40 0.50 RCI 0.60 0.70 0.80 0.90 12 Reservoir Complexity Index (RCI) – parameters used in evaluation Complexity score Complexity attribute Description Low complexity 1 Average permeability Describes the pore volume weighted average permeability in the main flow direction of the defined reservoir. mD > 10.000 Permeability contrast Describes the permeability contrast between geological layers/facies types, and is calculated as log10[Kmax/Kmin] <1 Structural complexity Describes how fluid flow between wells is affected by fault density, fault throw, fault transmissibility, …. Lateral stratigraphic continuity Describes the stratigraphic continuity of the flow units in the main flow direction within the defined reservoir STOOIP density Describes the areal concentration of STOOIP and is defined as STOOIP/area (mill. Sm3/km2) Coning tendency 08.02.07 Describes the coning problems associated with a gas cap or aquifer support. Large complexity only in cases where the oil band is thin. High complexity 2 100010 00 0 1-2 3 4 5 100-1000 10-100 < 10 2-3 3-4 >4 The fault properties restrict fluid flow significantly. (High density of faults with throw larger than reservoir thickness and/or 'zero' transmissibility). The fault properties does not restrict fluid flow. Highly discontinuous. Difficult to predict/describe injector/producer connecting flow units. High degree of continuity >4.5 No coning tendency. 2 - 4.5 1-2 Some coning problems from gas cap or aquifer 0.5 - 1 < 0.5 Thin oil zone and production severely restricted by gas or water coning problems 13 Important issues in estimating potential for different methods to increase recovery How is the remaining oil distributed in the reservoir? Temperature Fluid chemistry Mineralogy Topside facilities and wells Cost, both investment and operational Remaining field life Other issues 08.02.07 14 160 140 120 80 60 Frigg Snøhvit Odin Troll Alvheim Alvheim Balder Alvheim Draugen Gullfaks Gullfaks Gullfaks Heimdal Grane Balder Gullfaks Glitne Tordis Tordis Snøhvit Jotun Tordis Heidrun Skirne Statfjord Valhall Statfjord Øst Snorre Tordis Urd Snøhvit Sleipner Øst Gullfaks Sør Statfjord Hod Snorre Statfjord Nord Ormen Lange Mikkel Brage Statfjord Sygna Statfjord Nord Norne Gullfaks Sør Sigyn Sigyn Hod Frøy Gullfaks Sør Visund Njord Njord Gullfaks Sør Sleipner Vest Gullfaks Sør Lille-Frigg Vale Varg Gullfaks Sør Cod Vest Ekofisk Ekofisk Edda Albuskjell Ula Huldra Kvitebjørn Kristin Tambar Embla Mime Kristin 100 Deg. C Reservoir temperature in fields on NCS 180 40 20 0 Fields 15 08.02.07 Methods to improve injection ? To obtain better sweep and produce by-passed oil ? To reduce the residual oil saturation in the swept sone? Economical issues Environmental issues 08.02.07 16 Oil cost curve, including technological progress: availability of oil resources as a function of price 08.02.07 17 Cost and potential of Surfactant compared with other methods to increase recovery 08.02.07 18 Potential for surfactant flooding ? In 1991 a work group in Statoil, Hydro a Saga and NPD estimated a technical potential from 80 to 130 MSm³ Based on an Sorw > 0.25 and immediate startup in 10 reservoirs ”Profitable reserves (potential)” was estimated to 55 to 87 MSm³ including the condition of Seff > 40 Sm³ oil/ton surfactant Journal of Petroleum Science & Engineering, April 1992 What have16 years done to the potential? Is it time for a new potential study? 08.02.07 19
© Copyright 2024