GB/T 47442.1-2026Methods for potential evaluation of CO2 geological utilization and storage in oil and gas areas — Part 1: Geological utilization (English PDF)

4.1 Policy and regulatory documents

This includes national and local government action plans, regional development plans, financial support, and tax incentives for oil and gas reservoirs and surrounding carbon source areas. Legal documents.

4.2 Carbon Source Data

This includes the sources and distribution of carbon dioxide in industries such as coal chemical, refining, and power generation, carbon emissions, new capacity planning, and regional carbon market data. According to data such as regional carbon price gradients.

4.3 Geological data of oil and gas reservoirs

This includes regional data on the natural environment of the oil and gas reservoir to be evaluated, such as its geographical location, topography, hydrogeology, and other natural environmental factors, as well as the characteristics of the caprock and surrounding rocks, and the oil and gas reservoir itself.

Regional geological features, including structural and fracture characteristics, reservoir characteristics, fluid distribution and properties, reservoir pressure and temperature systems, and gas cap and edge water conditions.

For the compilation of basic data such as geological reserves and calibrated recovery rate, please refer to Appendix A.

4.4 Indoor Experimental Data

This includes core analysis experiments, rock mechanics experiments, high-pressure formation fluid property experiments, core displacement experiments, and minimum miscibility pressure experiments. Relevant data and information.

4.5 Production Data and Monitoring Information

This includes dynamic production data such as water injection volume, oil production, water production, formation pressure, water cut, gas-oil ratio, and recovery rate, as well as water absorption profiles and production data. Monitoring data such as liquid profile.

4.6 Engineering Data

This includes data related to wellbore and surface engineering, such as cementing and completion quality and casing material.

5.1 Screening Principles

Taking into account factors such as carbon dioxide injection capacity, geological body stability and sealing, and reservoir characteristics, the specific principles are as follows.

a) It does not conflict with the local natural environment, development plans, policies, and regulations;

b) The oil and gas reservoir has suitable burial depth, temperature and pressure conditions, reservoir permeability, pore connectivity, and fluid characteristics, allowing carbon dioxide to be effectively utilized. injection;

c) The oil and gas reservoir has a complete and stable geological structure, is far from active zones such as earthquake and volcanic areas, and the faults have closed boundaries and good lateral shielding.

The system's potential activity has a relatively small impact on the reservoir and caprock;

d) The caprock is continuously distributed and well-sealed, with no tensile penetrating faults, and the overlying layer has strong sealing ability. The direct caprock rocks are resistant to carbon dioxide.

Carbon dioxide is chemically inert and can exist stably for a long time.

5.2 Reservoir Screening

c) Considering available carbon sources, utilization rate of old wells in the oilfield, oil price, carbon price, total cost per barrel of oil, investment, taxes, depreciation, etc., analyze reservoir II. The economic feasibility of carbon dioxide flooding technology.

5.2.1 Determination of Minimum Miscibility Pressure

The minimum miscibility pressure of carbon dioxide with formation crude oil is determined using methods such as indoor experiments, theoretical derivation, reservoir analogy, or empirical formulas.

Force reference value. Select the range of screening parameters based on the miscibility pressure reference value.

5.2.2 Screening Requirements

Refer to Table A.1 to compile the collected basic reservoir parameters. For reservoirs that meet the screening criteria, further refinement is performed based on the key parameter ranges in Table 1.

This study analyzes the adaptability of carbon dioxide miscible flooding or immiscible flooding technologies in oil reservoirs. Suitable reservoirs for carbon dioxide miscible flooding or immiscible flooding should... It conforms to the requirements in Table 1.

5.2.3 Implementation Objectives

For the selected reservoirs, the carbon source situation, wellbore integrity, and economic feasibility are evaluated under current social, economic, and technological conditions, thereby... The following are recommendations for the current key implementation objectives.

a) Evaluate the wellbore integrity of the target reservoir, including the integrity of the wellhead equipment, the integrity of the wellbore structure, and the evaluation of wellbore corrosion, and analyze the second... Carbon dioxide leakage risk;

b) Using the selected target reservoir as the center, evaluate the surrounding carbon sources, comprehensively considering the carbon source scale, carbon source quality, source-sink distance, etc.

Considering the economics of capture and transportation, list suitable available carbon sources;

5.3 Gas reservoir screening

5.3.1 Screening Requirements

Refer to Table A.2 to compile the collected basic parameters of gas reservoirs. For gas reservoirs that meet the screening criteria, further refinement is performed based on the key parameter ranges in Table 2.

This study analyzes the adaptability of carbon dioxide flooding technology in gas reservoirs. Relatively mature carbon dioxide flooding technologies are used in water-gas reservoirs and condensate gas reservoirs.

For conventional gas reservoirs, those suitable for carbon dioxide flooding should meet the requirements of Table 2.

5.3.2 Implementation Objectives

For the selected gas reservoirs, evaluate their carbon source situation, wellbore integrity, and economic feasibility under current social, economic, and technological conditions, and provide... The following are recommendations for the current key implementation objectives.

a) Evaluate the wellbore integrity of the target gas reservoir, including the integrity of the wellhead equipment, the integrity of the wellbore structure, and the evaluation of wellbore corrosion, and analyze the second... Carbon dioxide leakage risk;

b) Using the selected target gas reservoir as the center, evaluate the surrounding carbon sources, comprehensively considering the carbon source scale, carbon source quality, source-sink distance, Considering the economics of capture and transportation, list suitable available carbon sources;

c) Considering available carbon sources, utilization rate of old wells in the oilfield, oil price, carbon price, total cost per barrel of oil, investment, taxes, depreciation, etc., analyze the gas reservoir II. The economic feasibility of carbon dioxide flooding technology.

6.1 Potential Forecasting Indicators

6.1.1 Oil Reservoir

6.1.1.1 Potential prediction indicators include the extent of enhanced oil recovery from carbon dioxide flooding to the end of its entire development lifecycle, and the increase in recoverable reserves. Quantity, effective amount of carbon dioxide to be stored.

6.1.1.2 Reservoirs that meet the requirements of Table 1 are suitable for carbon dioxide flooding, and their reserves are considered suitable reserves, and are classified as suitable carbon dioxide miscible phases.

There are two types of reservoirs. those suitable for carbon dioxide immiscible flooding and those suitable for carbon dioxide immiscible flooding.

Note: Oil reservoirs that are not suitable for production or storage under current technological conditions will not be subject to oil production or storage potential prediction.

6.1.2 Gas reservoir

6.1.2.1 Potential prediction indicators include the extent of enhanced oil recovery from utilizing carbon dioxide-driven gas extraction until the end of its entire lifecycle development, and the newly added recoverable reserves. Quantity, effective amount of carbon dioxide to be stored.

6.1.2.2 Gas reservoirs that meet the requirements of Table 2 are suitable for carbon dioxide flooding, and their reserves are suitable reserves.

Note: Gas reservoirs that are not suitable for gas production or storage under current technological conditions will not be subject to gas enhancement or storage potential prediction.

6.2 Methods for Predicting Potential for Increased Oil and Gas Production

6.2.1 Increase the recovery rate

The methods employed include physical simulation experiments, reservoir numerical simulations, analogies, and empirical formulas to determine the effectiveness of carbon dioxide-assisted oil or gas displacement. Reference values for the range of recovery rate.

6.2.2 New recoverable reserves from oil displacement

Suitable reserves for carbon dioxide flooding can be obtained through data collection or calculated using the volumetric method according to the provisions of DZ/T 0217.

Then, numerical simulation and other methods are used to calculate the new recoverable reserves after carbon dioxide flooding, or the recovery rate is increased according to formula (1).

6.2.3 New recoverable reserves from gas displacement

The appropriate reserves for carbon dioxide-driven gasification can be obtained through data collection or calculated using the volumetric method according to the provisions of DZ/T 0217.

Then, numerical simulation and other methods are used to calculate the new recoverable reserves after carbon dioxide displacement, or the recovery rate is increased according to formula (2).

6.3 Methods for Predicting Sequestration Potential

6.3.1 Reservoir Storage Potential

6.3.1.1 Total Seized Stock

In reservoirs developed using carbon dioxide flooding, considering the time scale, the calculation of carbon dioxide sequestration potential neglects the mineralization and sequestration mechanism, and the total... The amount of sequestration is the sum of the amount of construction sequestration, the amount of dissolution sequestration, and the amount of binding sequestration, calculated according to formula (3).

6.3.1.2 Construction of Seized Storage Quantity

Injecting carbon dioxide to restore reservoir pressure to its original formation pressure, and then using an equal amount of carbon dioxide to fill the underground space vacated by formation fluid extraction. […]

6.3.1.3 Dissolved and Sequestered Amount in Aqueous Phase

The amount of carbon dioxide dissolved and stored in the formation water phase is calculated according to formula (5).

6.3.1.4 Dissolved and Sequestered Amount in Crude Oil

The amount of dissolved carbon dioxide sequestrated in crude oil reservoirs is calculated according to formula (6).

6.3.2 Gas reservoir storage potential

6.3.2.1 Total amount of sealed inventory

In gas reservoirs developed using carbon dioxide flooding, considering the time scale, the calculation of carbon dioxide sequestration potential neglects the mineralization and sequestration mechanism, and the total... The amount of sequestration is the sum of the amount of sequestration constructed, the amount of sequestration dissolved, and the amount of sequestration bound.

6.3.2.2 Construction of Seized Storage Quantity

Injecting carbon dioxide to restore reservoir pressure to its original formation pressure, based on the underground space freed up by the produced fluids during gas drive, is equivalent to... Based on the ideal assumption of carbon dioxide occupation, for dry gas reservoirs, according to the material balance theory, the amount of carbon dioxide occupied by the structure is determined by formula (8). calculate.

6.3.2.3 Dissolution and Seal Amount

The dissolved and sequestered amount of carbon dioxide in the aqueous phase of a water-bearing gas reservoir is calculated using formula (5). The dissolved carbon dioxide in crude oil of a condensate gas reservoir... The amount of sealed stock is calculated using formula (6).

6.3.2.4 Binding and Sequestration Amount

The amount of carbon dioxide trapped and stored in the gas reservoir is calculated using formula (7).

6.3.3 Key Parameter Value Determination Method

It is advisable to utilize physical simulation experiments and numerical simulations of oil and gas reservoirs to obtain the relevant parameter values in the formula for the amount of oil reserves. Alternatively, methods with similar oil reserves can be used.

By analogy with known parameter values of typical blocks with specific conditions, key parameters can also be determined using empirical formulas and relational diagrams. Values are shown in Appendix B.