Shale In-Situ Conversion Parameter Optimization for Well Spacing

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Solution Overview

Problem

Existing shale oil in-situ conversion exploitation technologies lack effective methods for optimizing key parameters, leading to unreasonable exploitation approaches and high costs, making it difficult to guide the exploitation of shale oil with medium to low maturity effectively.

Innovation Solution

A method for predicting an optimal exploitation approach for shale oil in-situ conversion by determining optimal parameters through thermal simulation experiments, including the relationship between temperature rise rate and lower limit temperature, well distance between heater wells, and heating time, to optimize well patterns and yield equivalents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If existing horizontal well volume fracturing technique is used, then exploitation can be achieved for shale with medium to high maturity, but it is impossible to exploit shale with low to medium maturity due to poor porosity development and difficult fluid flow

Engineering Contradiction:
Improveadaptability to different shale maturity levelsVSAvoidexploitation effectiveness
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by transforming the exploitation approach from horizontal well volume fracturing to in-situ conversion technology. This involves changing the temperature parameter (heating the shale formation to convert organic matter into oil and gas) and the chemical parameter (converting unconverted organic matter into recoverable hydrocarbons). These parameter changes enable the system to adapt to low to medium maturity shale that cannot be effectively exploited by conventional fracturing methods.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If in-situ conversion technique is used for shallow oil shale, then exploitation of low to medium maturity shale becomes feasible, but the exploitation approach is unreasonable and cost is high

Engineering Contradiction:
Improvecapability to exploit low to medium maturity shaleVSAvoidexploitation cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies local quality by determining optimal exploitation parameters based on specific local conditions including shale thickness, organic matter content, maturity level, and thermal properties. The system calculates customized well spacing, heating rates, and conversion parameters for each target formation, rather than applying a uniform approach. This localized optimization reduces exploitation costs by matching the technical parameters to the specific characteristics of each shale formation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies dynamics by implementing a dynamic optimization system that adjusts exploitation parameters based on real-time calculations. The system dynamically determines well spacing, heating rates, and conversion timing based on thermal field simulations and economic parameters. This dynamic approach allows for continuous optimization of the exploitation process, improving cost-effectiveness compared to static, predetermined exploitation schemes.

Inventive Principle:
Principle #15Dynamics

3Productivity

If in-situ conversion is implemented without optimizing key parameters, then exploitation can proceed, but the approach is unreasonable and costs are high due to lack of parameter optimization

Engineering Contradiction:
Improveoil and gas productionVSAvoidparameter optimization system
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-calculating and determining optimal exploitation parameters before actual implementation. The system performs preliminary thermal field simulations, evaluates economic parameters, and determines optimal well spacing, heating rates, and conversion timing in advance. This preliminary optimization reduces complexity during actual exploitation by having predetermined parameters ready, rather than requiring complex real-time adjustments during the exploitation process.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces exploitation costs and provides scientific guidance for shale oil in-situ conversion by optimizing key parameters, ensuring efficient conversion of organic matter into oil and gas and maximizing resource utilization.

Implementation Method 1

an effective shale section is heated by utilizing a horizontal well or a vertical well, so as to convert the retained oil and gas as well as the unconverted organic matter

Methodology Applied
Scientific EffectThermal energy transfer: Conduction (thermal)

Implementation Method 2

determining optimal parameters through thermal simulation experiments, including the relationship between temperature rise rate and lower limit temperature, well distance between heater wells, and heating time

Methodology Applied
Scientific EffectThermal diffusion: Conduction (thermal)

Data Source

PatentEP3812983B1Method and device for predicting optimal development mode for shale oil in-situ conversion
Publication Date: 2026.04.22 PETROCHINA CO LTD
  • EP3812983B1 patent drawingFigure 1
  • EP3812983B1 patent drawingFigure 2A~2B
  • EP3812983B1 patent drawingFigure 3~4

AI summary

The disclosure provides a method and apparatus for predicting an optimal exploitation approach for shale oil in-situ conversion. The method includes: determining a lower limit temperature required for completely converting convertible organic matter in a shale to be measured into oil and gas, based on a pre-established relationship between the temperature rise rate and the lower limit temperature; determining an optimal well distance of heating wells, based on a thermal field parameter of a target reservoir of interest, an optimal heating time corresponding to the lower limit temperature, and a pre-established relationship between an optimal well distance of heating wells and the optimal heating time; determining an oil yield equivalent based on a temperature and an oil yield equivalent of the shale; determining an optimal well pattern; the lower limit temperature, the optimal well distance of heating wells, the oil yield equivalent and the optimal well pattern are optimal parameters. The above technical solution determines optimal exploitation approach for shale oil in-situ conversion based on optimal parameters obtained by optimizing key parameters during shale oil in-situ conversion and exploitation, so as to reduce the exploitation cost, and provide a scientific guidance for shale oil in-situ conversion exploitation.