What is the meaning of allocation meter?

Answer 1

Allocation is the process of assigning the proper portions of aggregated product flows back to

individual source streams, owners, leases or measurement point. The assignment process is a

standard method that is agreed upon and used by contracting parties. It is designed and intended

to be fair, cost efficient and practical. By providing an efficient product sales transaction

mechanism, allocation measurement helps to reduce capital and operating costs without

jeopardizing the principal goal of fair treatment among parties. Reducing fluid measurement

costs facilitates the development of marginal fields.

Allocation measurement can fall under federal or regulatory guidelines. Individual agreements

must meet or exceed those guidelines. API MPMS Chapter 20.1 is the industry's allocation

measurement standard. Without it volumes of technical measurement documents would be

required to accompany commercial contracts. The first edition of API 20.1 was prepared in 1993

and recently reaffirmed in 2006. Its scope is to provide a set of design and operating guidelines

for implementing liquid and gas allocation measurement systems. As such, it provides

recommendations for metering, static measurement, sampling, proving, calibrating, and

calculation procedures. Due to the breadth of the measurement topics covered under allocation

measurement, API Chapter 20.1 focuses on identifying procedures, providing practical and

technical guidance in implementing allocation metering systems, and acts, in part, as a master

guide to other important measurement guidelines.

Individual allocation meters determine the portion of flow that is attributable to an individual

source stream. The allocation meters may or may not meet custody transfer standards, although

the total production should be determined with custody transfer quality systems and procedures.

For example, it may be necessary to use multiphase metering with a higher degree of uncertainty

at some sites in order to reduce the requirement for separation equipment. Commingling of fluids

with differing qualities and properties leads to the need for periodic testing and validation in

order to better define the quality and quantity of the streams. Design, measurement equipment,

and practice choices must be made but they must be applied in a fair and uniform manner

throughout the system. Ultimately, the quality and quantity determinations in an allocation

system must represent the contributions from each individual source stream - lease contribution.

Existing custody transfer standards form much of the basis for the measurement methods used in

allocation. If Chapter 20.1 does not specifically address a measurement issue, then it should be

assumed that the appropriate custody transfer standards apply for that issue.