What is the principle of well logging?
Well logging is a means of recording the physical, acoustic and electrical properties of the rocks penetrated by a well. It is carried out by service companies, which work under contract for the oil companies.
Why do well logs start at different depths?
The differences between loggers and drillers depths are due to different stretch in the drilling string when drilling, and the wire line entered into the bore hole during wireline logging operations. This difference is estimated and referred to as “core shift”.
What should I look for in a well log?
You will need to know the legal description of the well location, and additional information that will be helpful include the drilling company that installed the well, the depth, the date drilled, and the original owner, if not you.
How many types of well logging are there?
Three type of logs: Gamma Ray Log, Neutron Ray Log and Density Log. A- GAMMA RAY LOG: -All substances are assemblages of atoms.
What are the 4 parameters that are evaluated in well logging?
The following Petrophysical parameters: porosity, water saturation, reservoir thickness and volume of shale were estimated for each hydrocarbon-bearing zone delineated for each well.
What are the types of logging?
Types of logging
- Circular logging. Use circular logging if all you want is restart recovery, using the log to roll back transactions that were in progress when the system stopped.
- Linear logging.
- Active log.
- Inactive log.
- Secondary log files.
How deep is the average well?
100 feet to 800 feet deep
Typical Depth of a Water Well
The typical depth of a residential well ranges from 100 feet to 800 feet deep. Some wells are even 1,000 feet or deeper. The deeper a well is, the better the water quality.
How do you read oil and gas logs?
Follow the Ko Ko Rules:
- Tight non-reservoir: Right-Right-Right-Right.
- Shale: Right-Right-Right-Left.
- Low porosity (tight) reservoir: Left-Right-Right-Right.
- Water bearing reservoir: Left-Left-Left-Left.
- Oil bearing reservoir: Left-Right-Left-Left.
- Gas reservoir: Left-Right-Left-Right.
What is a well log data?
Well logging allows a detailed record of the geologic formations penetrated by a borehole. The log is based on physical measurements made by geophysical tools lowered into the hole. Historically, the first logging measurements consisted of basic electrical logs (resistivity) and spontaneous potential (SP) logs.
What are the 4 types of logging?
Types of logs
- Electrode resistivity devices.
- Induction logging.
- Microresistivity logs.
- Spontaneous (SP) log.
What are the 3 types of logging?
The Three Types of Logging Systems
- Clearcutting. Many large-scale logging companies use the clearcutting method to harvest timber.
- Shelterwood. Another common logging technique is the shelterwood system.
- Selective Cutting.
What are the different types of logs?
Because of that, many types of logs exist, including:
- Event logs.
- Server logs.
- System logs.
- Authorization logs and access logs.
- Change logs.
- Availability logs.
- Resource logs.
- Threat logs.
What are test wells?
Test Well means a well, core hole, core test, observation well, or other well drilled from the surface to determine the presence of a mineral, mineral resource, ore, or rock unit, or to obtain geological or geophysical information or other subsurface data related to mineral exploration and extraction.
What are the 3 methods of logging?
What are 4 types of logging?
Do deeper wells mean better water?
Water quality in a deep well usually changes more slowly than in a shallow well. That’s because groundwater does some mixing as it moves through the aquifer. A spill a mile away from your deep well in the Basin and Range aquifer might be substantially diluted with clean aquifer water before it gets to your well.
What are the 4 types of wells?
4 Water Well Types That You Should Learn About
- Dug Well. Dug wells are shallow and they are not the best option for your drinking water.
- Bored Well.
- Driven Point Well.
- Drilled Well.
How long does it take to log an oil well?
The drilling of a modern shale well can take two to four weeks.
What are the three types of logging?
What are water logs worth?
Many of the sinker logs sold in the U.S. are sourced from the southern states, such as Louisiana or Florida. A cypress puller who intends to sell the wood directly to retail consumers may sell it for an average of one to four dollars per board foot.
What are the basic steps of logging?
The process from the ‘tree to mill’ can be broken down into 5 phases or five minor operations viz. the felling, processing, extraction, loading and transportation to saw mills or storage depots.
How do you calculate well Loss?
The well should be properly designed and developed to keep the well loss to a minimum. The step-drawdown test enables the determination of the well loss coefficient and also the well efficiency. Eq. (5.93a): Well efficiency = BQ/Sw × 100 = 5.49/11.29 × 100 = 48.7%.
How often should a well be tested?
At a minimum, check your well every spring to make sure there are no mechanical problems; test it once each year for total coliform bacteria, nitrates, total dissolved solids, and pH levels. If you suspect other contaminants, you should test for those as well.
How many years does a water well last?
The average lifespan for a well is 30–50 years. 2. How deep is the well? Drilled wells typically go down 100 feet or more.
How do well drillers know where to drill?
Geophysics methods can be used to identify the presence of water at depth. They are based on the changes in electric conductivity caused by the water. Finally bore holes can be drilled to assess the geological sequence of the strata and to identify layers potentially able to host an aquifer.