Logging objective
The first factor to consider when selecting a well logging tool is the logging objective, or what you want to measure and why. Different logging tools can provide different types of data, such as porosity, permeability, fluid saturation, lithology, fracture density, pressure, temperature, and so on. Depending on your drilling goal, you may need more or less data, or more or less detail, about certain aspects of the formation. For example, if you are drilling for oil or gas, you may want to focus on tools that can identify hydrocarbon-bearing zones, such as resistivity, nuclear, or acoustic tools. If you are drilling for geothermal energy, you may want to use tools that can measure the temperature and pressure gradients, such as thermometers or pressure gauges.
This article covers only four of the many factors and dimensions to consider during the logging program design process, which starts during the well-design stage when the business objectives of the logging program (answer products) and the type of logging tools available are considered in the selection of the well geometry, trajectory, drilling method, and drilling mud. The next step is to select the type of logging method (Logging-While-Drilling LWD or Wireline Logging WL) to use in each drilling stage (surface, intermediate, final).
Formation type
The second factor to consider when selecting a well logging tool is the formation type, or the physical and chemical characteristics of the rock and fluid layers that make up the subsurface. Different formations can have different effects on the performance and accuracy of logging tools, depending on their density, porosity, mineralogy, salinity, and so on. For example, some tools may not work well in formations that are highly conductive, such as salt or shale, or highly resistive, such as coal or limestone. Some tools may also be affected by the presence of gas or water in the formation, which can alter the electrical or acoustic properties of the rock. Therefore, you need to select a tool that can overcome or compensate for these formation effects, or use a combination of tools that can cross-check or calibrate each other.
Wellbore environment
The third factor to consider when selecting a well logging tool is the wellbore environment, or the physical and chemical conditions of the hole that the tool has to travel through. The wellbore environment can also influence the performance and accuracy of logging tools, depending on factors such as the diameter, depth, inclination, and deviation of the hole, the type and density of the drilling fluid, the presence of mud cakes or borehole breakouts, and so on. For example, some tools may not fit well in small or irregular holes, or may require a certain distance from the wall to operate properly. Some tools may also be sensitive to the interference or attenuation caused by the drilling fluid, or the noise or vibration generated by the drilling operation. Therefore, you need to select a tool that can adapt or adjust to these wellbore effects, or use a tool that can minimize or eliminate them.
Tool availability and cost
The fourth factor to consider when selecting a well logging tool is the tool availability and cost, or the practical and economic aspects of acquiring and using the tool. Different logging tools can have different levels of availability and cost, depending on their complexity, reliability, demand, and supply. For example, some tools may be more advanced or specialized, and therefore more scarce or expensive, than others. Some tools may also require more maintenance, calibration, or training, than others. Therefore, you need to select a tool that can meet your logging objective, formation type, and wellbore environment, while also being within your budget and time constraints, or use a tool that can offer the best value for money and quality for data.
By considering these four factors, you can select the right well logging tool for your formation, and obtain the most accurate and useful data for your drilling engineering project.
If you are looking for the world's leading downhole drilling and completion logging tools, be sure to get in touch with Vigor's professional team. Vigor's team of professional technical engineers have many years of on-site experience, and we can provide you with the most suitable solutions and the highest quality products based on your actual situation. We always adhere to the customer-centric business and service philosophy, and are committed to reducing costs and risks for our customers, achieving a win-win situation, and working together to promote the development of the oil and gas industry. We look forward to communicating and cooperating with you for the first time.
For more information, you can write to our mailbox info@vigorpetroleum.com & mail@vigorpetroleum.com
