JPT Compositional Simulation Artificial Intelligence Optimize Water Injection

The whole paper discusses optimization of a improvement plan involving low-salinity water injection (LSWI). This system combines compositional simulation and a mathematical optimization device that makes use of synthetic intelligence to maximise the web current worth (NPV) of the challenge beneath analysis. The tailored methodology allowed an optimum improvement plan, contemplating the uncertainty related within the reservoir, by use of a number of geostatistical realizations and simultaneous history-matched fashions.

LSWI

LSWI is an enhanced-oil-recovery approach by which the salinity of the injected water is managed with the target of accelerating the restoration issue. Of the mechanisms proposed for LSWI, wettability alteration is probably the most broadly accepted for describing the rise of the restoration issue. The wettability change in reservoirs with the presence of sandstones primarily is attributed to the multionic trade between the injected fluid and the clay floor, as is the double layer growth. From a technical perspective, the LSWI success is said strongly to reservoir lithology.

An built-in evaluation and optimization examine was carried out utilizing numerical simulation to judge LSWI in its place for rising the restoration issue within the Namorado subject within the Campos Basin of Brazil.

As a result of LSWI alters the preliminary chemical equilibrium and induces modifications within the system, the modeling of geochemistry is a basic a part of the simulation along with the compositional modeling of fluids. Throughout LSWI, the next three kinds of reactions can happen concurrently:

• Reactions within the aqueous part
• Mineral dissolution and precipitation reactions
• Ion-exchange reactions

Contemplating that the chemical modifications generated within the reservoir throughout LSWI induce the wettability alteration, this impact have to be factored into the modeling. The impact of the wettability alteration is modeled by modifying the relative permeability curves utilizing an interpolant because the equal fraction of an ion topic to cation trade on the floor of the rock—the species molality within the aqueous part or the mineral quantity (fraction). Definition of a number of relative permeability curves for a similar sort of rock is feasible, whereby every group of curves corresponds to an outlined interpolant worth. Typically, two teams of relative permeability curves are outlined, the primary representing the situations of high-salinity water injection (HSWI) and the second these of LSWI.

Mannequin Description

The mannequin used as a reference for the present simulation examine corresponds to an artificial mannequin for improvement and reservoir administration purposes that represents the Namorado subject. The structural traits, facies, petrophysical properties, fluid properties, properly data and manufacturing historical past information have been obtained from public information for the Namorado subject supplied by the Nationwide Petroleum Company of Brazil.

The examine evaluated HSWI and LSWI as restoration methods; the reference mannequin information have been used to construct a mannequin suitable with a industrial compositional simulator.

The simulation mannequin corresponds to a corner-point grid with 81×58×20 cells (100×100×8 m), of which 38,466 are energetic cells (Fig. 1). The fluid mannequin has seven pseudocomponents that characterize 33.18 °API crude. The reservoir has a reference stress of 32 068 kPa at a reference depth of 3000 m. The water/oil ­contact depth was outlined at 3100 m.

LSWI Optimization Methodology. A software program device that mixes superior statistical evaluation, machine studying, synthetic intelligence, and data-interpretation methods was used to maximise challenge NPV. The optimization challenge was executed in three phases.

Assisted Historical past Match. For the Namorado subject, the simulation begin was outlined as 1 June 2013. Historic information data have been reported for 4 vertical producing wells for 4 years. With this data, the assisted history-matching technique of the simulation mannequin was carried out to create mixtures of the most-influential parameters to attain the historical past match.

For the Namorado subject, assisted history-matching parameters are associated to rock compressibility. Water/oil relative permeability curve parameters and porosity permeability and web/gross ratio distributions have been thought of. For the sector, 500 equiprobable geological realizations can be found by which the attributes of porosity, permeability, and web/gross ratio are outlined. The porosity distribution was estimated on the premise of subject facies distribution, in addition to the web/gross ratio, whereas the permeability distribution was decided on the premise of porosity.

The relative water/oil permeability curves have been modeled utilizing the Corey equation. A Bayesian optimizer was used to acquire the fashions with the perfect historical past match, minimizing the worldwide error between the simulated and the historic information for the cumulative oil, water, and fuel manufacturing; common reservoir stress; and properly bottomhole stress for every properly. For this examine, an appropriate historical past match occurred when the worldwide error was equal to or lower than 5.5%. The outcomes obtained for the worldwide error operate current errors within the vary of three.62 to five.44%.

The history-matching outcomes obtained for the oil, fuel, and water cumulative manufacturing set up that the Bayesian optimization algorithm obtained fashions with a very good illustration of historic information.

Likelihood Forecast. Utilizing the 50 finest instances obtained from the assisted historical past match, the manufacturing probabilistic forecast for a interval of 26 years was carried out beneath a main manufacturing scheme (or base case) of the 4 vertical producing wells within the subject. Through the forecast, the wells have been constrained by the final pressure-drop worth, recorded individually for every on the finish of the historical past match. Moreover, a most liquid charge constraint of 2000 m³/d and a minimal properly bottomhole stress of 17 632 kPa have been imposed. As a well-­monitoring constraint, a minimal oil manufacturing charge of 20 m³/d and a fuel/oil ratio of 200 m³/m³ have been outlined.

The first manufacturing scheme was used as a base case to interpret subject manufacturing conduct if the present improvement plan is sustained; moreover, it was used to quantify the incremental oil-recovery issue throughout the analysis of a special improvement plan. On the premise of the gathered oil manufacturing values, the eventualities P10, P30, P50, P70, and P90 have been chosen and have been subsequently used as base case for the choice and optimization of the restoration technique.

Sturdy Optimization. Contemplating that the strong work stream entails a number of optimization eventualities concurrently, two completely different examine classes have to be outlined, termed because the grasp examine and dependent research.

The grasp examine is chargeable for producing experiments based on the design outlined by the optimization algorithm. The experiments created by the grasp examine are executed for all dependent research. For every dependent examine, the values of the target features are calculated after which transferred to the grasp examine to calculate the general goal operate.

Dependent research are used to characterize every of the chosen realizations within the probabilistic forecast. This permits analysis of the uncertainty related to the distribution of properties reminiscent of porosity, permeability, and web/gross ratio within the NPV optimization course of.

The target operate outlined for the dependent research was the NPV. The NPV on this case consists of 5 phrases representing the preliminary funding in floor amenities and new wells, revenues from the oil gross sales, oil-production prices, and water produced and injected value. The strong goal operate was outlined as the typical NPV calculated for every of the dependent research.

The optimization technique carried out roughly 240 simulation jobs to acquire the optimum NPV. The optimum case exhibits that the restoration technique to be carried out is LSWI, which reaches an NPV of $2,453,000,000 utilizing a complete of 18 new wells (12 are producers, and 6 are injectors).

The values obtained for the NPV in every dependent examine are consolidated. For the Namorado subject, the NPV for the P10 situation was $1,807,000,000, whereas, for the P90, it was $3,315,000,000.

With regard to the restoration issue, the perfect technique to implement is LSWI as compared with typical water injection. Within the optimum LSWI case, for situation P10 the restoration issue was 40.75%, whereas, for P90, it was 42.21%.