When Weatherby Energy engages in the process of drilling for natural resources, such as oil, gas, or minerals, the hole that is drilled is referred to as a well bore. Weatherby Energy has many tools used to examine the well bore and to increase the chances of being able to successfully find oil or gas. Some of these involve investigation down in the well bore, while another way to examine the geological structures around the bore hole is to look at the samples that are brought to the surface during the drilling operation.
In recent years logging has also been combined with the drilling operation and is called Logging While Drilling. This means logging tools are integrated with the drill string as part of the bottom hole assembly and the measurements can be made while drilling is occurring.
Regardless, whether data comes from down in the bore or through bringing samples up, Weatherby Energy makes careful use of something called well log analysis.
Understanding Well Log Analysis
Weatherby Energy uses many tools to examine the structure and resistivity of rock, as well as tools that measure seismic activity, and tools that record radiation. These tools are connected to a long cable called a wireline and are lowered into the well bore.
Information from these tools and inspections is compiled into the well log. This is a detailed account of the geological formation around the well bore. If the log is made from the samples, it is called a geological log. If it is based on the wireline tools, it is called a geophysical log.
Compiling Well Logs
Well logs are compiled by Weatherby Energy for both open hole operations and cased hole operations. Open hole means the well has just been drilled and the wireline tools will help to evaluate the reservoir. Information gathered will cover the presence of oil or gas, amount of saturation of oil and water, and the permeability, density, and physical characteristics of the rock formations. Well logs for cased hole operations are made to help the finished well produce at optimum levels. After drilling ceases, the well bore is fitted with steel casings using cement. The data will include the quality of the cement, the characteristics of surrounding rock, and how much the well is producing.
The main purpose of a log is to gather information on the geophysical properties of the surrounding rock formations. This includes not only porosity and permeability but also the kinds of fluids that are contained there. Having a lot of data about the formations will help with recovery of the maximum amount of hydrocarbons and will give you an idea of the damage that will occur to the formations.
Other things that are measured by Weatherby Energy include the sound waves (seismic waves) to show how hard the rock is and any fractures that are present. The natural radiation of the rock is measured in gamma rays and neutrons. Shale emits quite a lot of gamma rays and this information is useful. The density of the rock is also recorded with this measurement.
A well log called the mud log, which is a geological log, is also useful. Mud is used in the drilling process and analyses of the mud can give you the speed at which you are drilling, the properties of the formations, percentage of hydrocarbons, pressure, temperature, viscosity, and more.