Based on the geological and geophysical conditions, the comprehensive logging method can be reasonably selected to study the geological profile of the borehole in detail, detect useful minerals, and provide detailed data necessary for calculating reserves, such as the effective thickness and pores of the oil layer. degree, oil and gas saturation and permeability, etc., as well as research on drilling technology and other tasks. In addition, methods such as in-hole magnetic logging, in-hole excitation excitation, in-hole radio wave perspective and gravity logging can also discover and study blind ore bodies near boreholes. Well logging methods are widely used in drilling of petroleum, coal, metal and non-metal minerals, hydrogeology, and engineering geology. Especially in oil and gas fields, coal fields and hydrogeological exploration work, it has become one of the indispensable exploration methods. The application of well logging methods can reduce the workload of drilling and coring, increase the exploration speed, and reduce exploration costs. In oil fields, well logging is sometimes called mine geophysical exploration, oil mine geophysics or geophysical well logging.
Well logging has been an important method and technology for the exploration and development of oil and gas fields for nearly 80 years. With the advancement of science and technology and the development of logging technology itself, it plays a greater role in the entire process of oil and gas exploration, development and production, bringing higher economic benefits to the oil and gas industry.
Logging technology has made significant progress in the past decade or so, especially since the 1990s. According to the traditional view, logging technology in oil and gas exploration and development only does some quantitative or Semi-quantitative evaluation work is far behind the needs of the rapid development of the oil and gas industry. The theories, methods and technologies for evaluating oil and gas reservoirs in today's well logging work have made great progress, and the field of solving geological problems is also gradually expanding. At present, geophysical logging research and solving oil and gas exploration and development problems include the following aspects.
Research on basic geological issues of oil and gas reservoirs
1) Use geophysical logging information to divide and calibrate stratigraphic sequences.
2) Use well logging data to conduct research on the fine geological structure and faults of oil and gas reservoirs.
3) Guided by the basic theories of structural geology, through structural stress analysis and full use of well logging information, we conduct quantitative research on fractured reservoir zones and understand the distribution patterns of fracture development.
4) Research on geophysical well log sedimentology, integrate other geological data, conduct analysis of sedimentary microfacies, and establish the depositional environment and ancient water flow direction.
Geophysical well logging is a means and basis for solving problems related to mineral resource geology, engineering geology, disaster geology, ecological environment and other issues. It is a conditional indirect reflection of the actual geological conditions in the drilling well. The well logging must be Only when information is deeply processed and converted into geological information, engineering information, disaster geology, ecological environment and other information can we achieve the purpose of understanding and solving problems.
1) Use geophysical well logging information to interpret and evaluate oil, gas, and water layers, and calculate the porosity, permeability, and oil (gas) saturation of oil and gas rock series.
2) Use well logging information to study oil layers, caprocks and oil and gas generation, storage and caprock combinations.
3) Use well logging information to study oil reserve parameters, underground fluid properties, and distribution conditions.
In addition, logging work can also be used for quantitative analysis of modern geostress fields, predicting and monitoring formation pressure and fracture pressure, and providing a basis for rational development of oil and gas and scientific drilling.
Geophysical logging is a technical discipline that is still developing rapidly. With the increasing difficulty of developing oil and gas and other mineral resources and the rapid development of science and technology, new logging theories, new methods, and new technologies have also are constantly emerging and developing.