Bringing OLI MSE into PHREEQC for reservoir simulations Application to subsurface challenges

Transcription

1 Bringing OLI MSE into PHREEQC for reservoir simulations Application to subsurface challenges OLI Simulation Conference 2016 Tim Tambach, Niko Kampman, and Jeroen Snippe Storage and Containment Technologies With acknowledgement to Lingli Wei (Shell) and Peiming Wang/other OLI staff 1

2 Definitions & Cautionary Note Reserves: Our use of the term reserves in this presentation means SEC proved oil and gas reserves. Resources: Our use of the term resources in this presentation includes quantities of oil and gas not yet classified as SEC proved oil and gas reserves. Resources are consistent with the Society of Petroleum Engineers 2P and 2C definitions. Organic: Our use of the term Organic includes SEC proved oil and gas reserves excluding changes resulting from acquisitions, divestments and year-average pricing impact. Shales: Our use of the term shales refers to tight, shale and coal bed methane oil and gas acreage. The companies in which Royal Dutch Shell plc directly and indirectly owns investments are separate legal entities. In this presentation Shell, Shell group and Royal Dutch Shell are sometimes used for convenience where references are made to Royal Dutch Shell plc and its subsidiaries in general. Likewise, the words we, us and our are also used to refer to subsidiaries in general or to those who work for them. These expressions are also used where no useful purpose is served by identifying the particular company or companies. Subsidiaries, Shell subsidiaries and Shell companies as used in this presentation refer to companies over which Royal Dutch Shell plc either directly or indirectly has control. Entities and unincorporated arrangements over which Shell has joint control are generally referred to joint ventures and joint operations respectively. Entities over which Shell has significant influence but neither control nor joint control are referred to as associates. The term Shell interest is used for convenience to indicate the direct and/or indirect ownership interest held by Shell in a venture, partnership or company, after exclusion of all third-party interest. This presentation contains forward-looking statements concerning the financial condition, results of operations and businesses of Royal Dutch Shell. All statements other than statements of historical fact are, or may be deemed to be, forward-looking statements. Forward-looking statements are statements of future expectations that are based on management s current expectations and assumptions and involve known and unknown risks and uncertainties that could cause actual results, performance or events to differ materially from those expressed or implied in these statements. Forward-looking statements include, among other things, statements concerning the potential exposure of Royal Dutch Shell to market risks and statements expressing management s expectations, beliefs, estimates, forecasts, projections and assumptions. 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There are a number of factors that could affect the future operations of Royal Dutch Shell and could cause those results to differ materially from those expressed in the forward-looking statements included in this presentation, including (without limitation): (a) price fluctuations in crude oil and natural gas; (b) changes in demand for Shell s products; (c) currency fluctuations; (d) drilling and production results; (e) reserves estimates; (f) loss of market share and industry competition; (g) environmental and physical risks; (h) risks associated with the identification of suitable potential acquisition properties and targets, and successful negotiation and completion of such transactions; (i) the risk of doing business in developing countries and countries subject to international sanctions; (j) legislative, fiscal and regulatory developments including regulatory measures addressing climate change; (k) economic and financial market conditions in various countries and regions; (l) political risks, including the risks of expropriation and renegotiation of the terms of contracts with governmental entities, delays or advancements in the approval of projects and delays in the reimbursement for shared costs; and (m) changes in trading conditions. All forward-looking statements contained in this presentation are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. Readers should not place undue reliance on forward-looking statements. Additional risk factors that may affect future results are contained in Royal Dutch Shell s 20-F for the year ended December 31, 2015 (available at and ). These risk factors also expressly qualify all forward looking statements contained in this presentation and should be considered by the reader. Each forward-looking statement speaks only as of the date of this presentation,. Neither Royal Dutch Shell plc nor any of its subsidiaries undertake any obligation to publicly update or revise any forward-looking statement as a result of new information, future events or other information. In light of these risks, results could differ materially from those stated, implied or inferred from the forward-looking statements contained in this presentation. We may have used certain terms, such as resources, in this presentation that United States Securities and Exchange Commission (SEC) strictly prohibits us from including in our filings with the SEC. U.S. Investors are urged to consider closely the disclosure in our Form 20-F, File No , available on the SEC website 2

3 Introduction to reservoir simulation and reactive transport modelling (RTM) 1 3

4 Challenges in the oil and gas industry Subsurface activities that potentially involve geochemistry Water flooding CO 2 / H 2 S injection Geochemical impact attracts more attention Operational technical challenges (e.g. scaling, souring) Long-term storage and conformance (safety) Forecast using reactive transport modelling (RTM) Fluid and gas flow in porous media (which area is affected?) Geochemical impact of subsurface activities Source: TNO 4

5 RTM with MoReS-PHREEQC started in D geology Oil-Gas-Water PVT Fluid flow Aqueous chemistry Water-rock interactions MoReS MoReS (Reservoir simulation) PHREEQC v3 (Geochemical modelling) The Shell reservoir simulator MoReS is coupled to open-source geochemical software PHREEQC 5

6 Which geochemical database to be used? Geochemical databases distributed with PHREEQC give different results (Dethlefsen et al., 2011) From: Dethlefsen et al., Environ. Earth Sci Criteria for a MoReS-PHREEQC geochemical database Should be verified against experimental data Should be consistent with data used by various other disciplines involved in our projects (e.g. production chemistry, wells) 6

7 Link the OLI MSE database to MoReS-PHREEQC 3D geology Oil-Gas-Water PVT Fluid flow Aqueous chemistry Water-rock interactions MoReS MoReS (Reservoir simulation) PHREEQC v3 (Geochemical modelling) MSE geochemical database from OLI Stream Analyzer fulfills the criteria Stream Analyzer (MSE) (Production Chemistry) 7

8 Mapping of MSE geochemical reactions to PHREEQC 2 8

9 Description of geochemical reactions in PHREEQC and OLI Stream Analyzer Dissociation of dissolved calcite: CaCO 3 (aq) Ca 2+ (aq) + CO 3 2- (aq) K = m Ca 2+m CO 3 2 m CaCO3 γ Ca 2+γ CO3 2 γ CaCO3 K and are pressure/ temperature dependent depends on the aqueous Equilibrium constant (K) Molality (m) Activity coefficient ( ) composition PHREEQC and OLI use different models to parameterize K and 9

10 Mapping of K and Equilibrium constant (K) Stream Analyzer uses Helgeson-Kirkham-Flowers equation of state (HKF-EOS) PHREEQC uses expression (P=1 bar): log 10 K = A 1 + A 2 T + A 3 T + A 4 log 10 T + A 5 T 2 + A 6 T 2 Solved by fitting Stream Analyzer results to the PHREEQC expression PHREEQC uses HKF-EOS for P-dependency map parameters directly Activity coefficient ( ) Stream Analyzer uses MSE model [Wang et al., Fluid Phase Equilibria 203 (2002)] PHREEQC uses various activity models (incompatible with MSE) Solved by implementing MSE model into the PHREEQC source code Mapping done for ~100 aqueous species, ~300 minerals, and ~10 gases 10

11 Molality (mol/kgw) log K (-) Activity coefficieint (-) Mapping carried out successfully 10.0 P=1 bar CaCO3 (OLI) 2.0 Fit (PHRQC) 0.7 P=300 bar Ca+2 (OLI) 0.4 Ca+2(PHRQC) T ( C) P=300 bar T ( C) Very good of fit of K Ca+2 (OLI) 0.01 Ca+2(PHRQC) T ( C) Activity coefficient and molality well-reproduced Similar conclusions for other reactions and species 11

12 We carry out our own verification of OLI Stream Analyzer results with experimental data Palmer et. al 2001 Example - boehmite [AlO(OH)] Left equilibrium constant Right dissolution with ph at 1.0M NaCl 12

13 Forecast of reactive CO 2 injection into a carbonate formation 3 A brief insight 13

14 CO 2 is reactive, but how reactive? CO 2 storage to mitigate climate change Carbonate reservoirs are abundant in the Middle East Dissociation of CO 2 in the formation water (FW) of the reservoir CO 2 (aq) + H 2 O HCO 3- (aq) + H + (aq) Geochemical reactions in the reservoir Dissolution of initially present calcite (and dolomite) New minerals are formed (anhydrite and celestine) Simulations with RTM to study the dynamics 14

15 Long-term migration of CO 2 in the reservoir Modelling of 30 years of CO 2 injection + additional 970 years Based on geological model with spatial variation in porosity/permeability Geological sealing layer prevents upward migration injection well cross section through the well map view of upper layer From: T.J. Tambach, J. Lonnee, and J.R. Snippe. Forecast of reactive CO 2 injection into a carbonate formation, Middle East. Proceedings of the 13 th International Conference on Greenhouse Gas Control Technologies, GHGT-13, November 2016, Lausanne, Switzerland 15

16 Long-term geochemical effects in the reservoir From: T.J. Tambach, J. Lonnee, and J.R. Snippe. Forecast of reactive CO 2 injection into a carbonate formation, Middle East. Proceedings of the 13 th International Conference on Greenhouse Gas Control Technologies, GHGT-13, November 2016, Lausanne, Switzerland Map views of ph (left), change in calcite (middle), and change in porosity (right) ph reduces from 7.0 to 4.6 calcite dissolution (<0.1%) is the most dominant mineral reaction porosity change is up to 0.03% 16

17 Barite scaling due to waterflooding of an oil-producing field 4 A brief insight 17

18 SI BaSO4 (-) Geochemistry of waterflooding matters Oil and formation water (FW) are present in the reservoir rock Sea water (SW) is injected to stimulate oil production FW has a relatively high Ba 2+ concentration (SO 4 2- is small) SW has a relatively high SO 4 2- concentration (Ba 2+ is small) 3 Mixing of SW and FW could lead to barite (BaSO 4 ) precipitation (scaling) Reduces the permeability of the rock/well Productivity decline Simulations with RTM to predict the impact -1 computed with Stream Analyzer (MSE) Volume fraction SW (-) 18

19 SW plume reaches various production wells We use Cl - to monitor the SW plume Cl - does not react Cl - molality in the SW is ±70% of the Cl - molality in the FW BaSO 4 precipitation is simulated in the plume area 19

20 Ba (mol/kgw) S (mol/kgw) SI BaSO4 (-) Production data with time for a certain well 4.0E E-03 His His - EDTA Sim SimNoMin 1.0E E E-02 His His - EDTA Sim SimNoMin His His - EDTA Sim SimNoMin 2.0E E E E E Time (yr) 1.0E Time (yr) Time (yr) Simulations show reasonable agreement to historical data Simulations predict that scaling could become a problem in the near future We recommended a scale squeeze (preventing BaSO 4 precipitation) to the responsible team of this specific field 20

21 Conclusions 5 21

22 Summary and conclusions Successfully mapped OLI MSE geochemical data to MoReS-PHREEQC Currently contains ~100 aqueous species, ~300 minerals, and ~10 gases Stimulates project work where other disciplines are involved Parts of the geochemical database are confidential Demonstrated the use of RTM with OLI MSE geochemical data for two case studies Relatively small geochemical impact of CO 2 storage in carbonate reservoirs Scale squeeze recommendation to prevent barite scaling and productivity decline Combination of RTM and OLI MSE geochemical data assists our decision making for various reservoir engineering challenges 22

23 Questions and Answers 23

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