Passenger ships should carry the marking on a horizontal surface visible from the air. Ships should also be marked with their ID numbers internally.
The IMO ship identification number scheme was introduced in through adoption of resolution A. It aimed at assigning a permanent number to each ship for identification purposes. In states with very few wells, the unique number may be based on the permit number, and may be unique within the state rather than the county.
This is an unusual situation. There are four types of unique well identifiers, and these are called historical, current, reserved, and exempt. Historical API numbers were assigned by Petroleum Information or other service companies and cooperative groups.
In most states, wells drilled before have historical numbers. These numbers range in value from to , so would be a typical historical number. Current API numbers are assigned by regulatory agencies, usually the oil and gas commission for the state where the well was drilled.
These numbers are assigned as part of the well permitting process, and they may be the same as the well permit number. Current numbers are numbered sequentially beginning from with some exceptions. In the example above, is a current number. Some states have deviated from this recommended system because of their own needs or previously established systems.
Illinois and North Dakota have no break between their historical and current well numbers. Arkansas started its current numbers at , while Texas started at Colorado , Michigan , and Utah have special numbering systems. The wells in the Federal waters of offshore Texas and Louisiana started at These were for wells that for some reason were not assigned a number by the regulatory agency. If PI deemed the well deemed "information important," it received a number between and There are eight types of wells that may have received a reserved number.
These are stratigraphic or core tests , water supply wells , water disposal wells , water or gas injection wells , sulfur wells , underground storage wells , geothermal wells , or prospect tests. Exempt numbers range in value from to These numbers are proprietary, and may not be assigned by any regulatory agency or data vendor like Petroleum Information. This allows the oil company to include information on any wells that are "information important" but confidential.
The sidetrack code is the eleventh and twelfth digits 03 in the example above of the API number. The original vertical well is normally The first directional sidetrack would then be In some states, the regulatory agency assigns the sidetrack codes, while other regulatory agencies do not. This means that the sidetrack code is useful in some places, but not used in others.
The thirteenth and fourteenth digits 00 in the example above are to distinguish between separate operations in a single bore hole. In , the API Subcommittee on Well Data Retrieval Systems proposed adding the event sequence code to deal with re-entries, recompletions, and hole deepenings.
However, because of industry conditions low oil prices , the subcommittee was disbanded before the recommendations were published and adopted by API . However, this event sequence code is assigned by IHS Energy, and is not found in most oil and gas databases. There are primary and secondary sources for API numbers. After that date, most numbers were assigned by the various state oil and gas regulatory bodies. The state commissions are therefore the primary, authoritative source for API numbers.
Most oil and gas commissions make API numbers and well header data available on-line and free of charge. The ability to download the data varies from state to state. Below is a list of the 50 states, along with their state code, and the name and internet address of their oil and gas regulatory agency where available. This list is partially based on information available from the Railroad Commission of Texas .
IHS is now a secondary source for API numbers for most states, since they do not have assigning authority. Other secondary sources include commercial vendors of oil and gas data.
API numbers are also used in many private corporate databases. From Wikipedia, the free encyclopedia. Archived from the original on Retrieved from " https: