GB/T 24504-2025 in English

Chapter 7 details the complete well testing process, including test preparation, string running, equipment installation, string pressure testing, drilling fluid replacement, packer setting, pressure balancing, injection/pressure drop testing, and in-situ stress testing.

Key quality control points during the well testing process include: circulating the well to ensure wellbore patency, verifying pressure gauge programming, passing the string pressure test, replacing drilling fluid with clean water, and verifying packer setting. Each step must be strictly carried out in accordance with the standard requirements, and detailed records must be maintained.

Data Collection and Recording Specifications

Chapter 8 of the standard sets out clear requirements for data recording and collection. Field operation records must include tubing string data, raw test data, and work logs. Pressure gauge data collection requires different acquisition frequencies depending on the test phase:

• Tubing string tripping phase: no more than 60 seconds
• Injection phase: 10-20 seconds (injection/pressure drop test) or 1 second (in situ stress test)
• Shut-in phase: 3 hours and 3 seconds in the initial phase, 5 hours and 5 seconds in the middle phase, and 10-20 seconds in the later phase

Well Test Data Interpretation Methods

Chapter 9 specifies the technical requirements for well test data interpretation, including basic diagram creation, parameter selection, analysis model selection, conventional analysis, typical curve fitting analysis, and result verification.

Well test interpretation requires the creation of seven basic diagrams, such as pressure-temperature curves, semi-logarithmic analysis charts, and double-logarithmic analysis charts. During the interpretation process, consistency and reliability tests are required to ensure the accuracy and reliability of the interpretation results.

Implementation Recommendations and Precautions

Based on the standard's content, the following implementation recommendations are proposed:

Equipment Selection Recommendations: Prioritize high-precision electronic pressure gauges and reliable downhole shut-in tools that meet standard requirements to ensure data acquisition quality.

Construction Organization Recommendations: Develop a detailed construction plan and quality control plan, clearly defining the responsible individuals and acceptance criteria for each step.

Data Processing Recommendations: Use professional well test interpretation software for data analysis, while also performing manual proofreading to ensure the rationality of the interpretation results.

Safety and Environmental Protection Recommendations: Strictly adhere to well control requirements and environmental regulations to ensure safe and environmentally friendly well testing operations.

Prospects for Standard Application

The implementation of GB/T 24504-2025 will further enhance the standardization of coalbed methane well testing technology in my country and provide technical support for efficient coalbed methane development. As coalbed methane exploration and development deepens, this standard will play an important role in reservoir evaluation, production capacity prediction, and development plan optimization.