Glossary
API - American Petroleum Institute
Capital costs - one-time costs that account for costs associated with adding new wells, facilities or pipelines to the gathering system. Examples of capital costs might be the finding, drilling and completion costs for a well, the design, procurement and installation of a compressor, or the build-out of a new pipeline.
Converge - the residual error for pressure and rate from one iteration to the next is below the tolerance set in the software.
Discount rate - the rate by which future revenues, costs, and cash flows are discounted back to a present value.
Entity – any facility that can be defined at a certain location. This can be a node, delivery point, well, separator, and so on.
EUR - Estimate Ultimate Recovery
Fixed rate well - A fixed fluid rate is defined; the well flows at the rate specified independent of the wellhead pressure. A fixed rate well does not have a primary fluid so there is one well type for oil, gas and water wells.
Gathering system - the infrastructure by which hydrocarbons are transported from wells to the point of sale. This system may consist of pipes, compressors, separation units (separators, amine plants and refrigeration units), and so on. A gathering system must be connected to a delivery point (point of sales) for Piper to run calculations.
Inflation rate- the rate by which future fixed and variable monthly costs will be incremented into the future.
Injection system - the infrastructure by which fluids are injected into wells. This system may consist of pipes, compressors, separation units (separators, amine plants and refrigeration units), and so on. An injection system must be connected to a delivery point (point of sales) for Piper to run calculations.
Labor costs - costs associated with installation and tie-in of the pipeline. Labor costs are defined on a $/mile ($/km) basis.
Link – the pipeline connection between any two points.
Material costs - costs directly associated with procuring the length and diameter of pipe desired.
Model - the gathering or injection system created in Piper.
Monthly fixed operating costs - a fixed, system-level cost (i.e.,. a cost that can not be associated with any particular facility) applied every month, for example, field operator, pigging programs, or land leasing costs.
Monthly operating costs - fixed costs that occur on a monthly basis, for example, compressor maintenance, replacement parts, and salaries.
mpp - mid point of perforation
Profile well - a fixed deliverability well that provides a profile of fluid rates that change by time interval. Profile wells are not affected by changes in wellhead pressure.
PVT - Pressure, Volume, Temperature
Specific gravity -the process of taking a sample fluid and finding its density at a certain temperature and pressure then comparing that to the density of a reference fluid at the same temperature and pressure. For oil and gas, the temperature and pressure combination is usually at standard conditions.
Gas gravity -Pure air is the reference fluid. Since most natural gas is less dense than air, the ratio is in the range of 0.55 < SG < 1
Oil (API) gravity - Pure water is the reference fluid. Oil is usually less dense than water.
Water specific gravity - Pure water is the reference fluid. The default is 1.0000. However, a lot of reservoir water is brackish, so it can be more dense, approximately 1.01.
Variable operating costs - costs that depend on the amount of gas being produced., for example, H2S management, or liquid disposal costs.
Well – a defined location where rate enters the gathering system. It is intended to represent the location of an actual well, and can be represented with either a simple or complex deliverability model.