High Island Offshore System, L.L.C.

Third Revised Volume No. 1

Effective Date: 04/07/1999, Docket: GT99- 17-000, Status: Effective

Original Sheet No. 78 Original Sheet No. 78 : Effective

GENERAL TERMS AND CONDITIONS

(Continued)

3. MEASUREMENT

3.1 Unit of Measurement and Metering Base. The volumetric

measurement base shall be one cubic foot of Gas at a

pressure base of 14.73 pounds per square inch absolute, and

a temperature base of 60 degrees Fahrenheit (on a dry

basis).

3.2 The unit of gas received and delivered by Transporter shall

be 1 Dth. The number of Dth shall be determined by

multiplying the number of standard cubic feet of gas

measured on the measurement basis described in this

section, by the total Heating Value of such gas in Btu per

standard cubic foot as defined in Section 4.2 below, and by

dividing the product by 1 million (1,000,000). For

reporting purposes, Btu conversion factors should be

reported to not less than 3 decimal places and Pressure Base

conversion factors should be reported to not less than 6

decimal places. For calculation purposes, not less than 6

decimal places should be used for both conversion factors.

3.3 Atmospheric Pressure. The average absolute atmospheric

(barometric) pressure shall be assumed to be 14.73 pounds

per square inch, irrespective of actual elevation or

location of the points of measurement above sea level or

variations in actual barometric pressure from time to time.

3.4 Temperature. The temperature of the Gas shall be determined

at each point of measurement by means of a properly

installed recording thermometer or temperature transmitter

of standard manufacture acceptable to both parties.

3.5 Specific Gravity. The specific gravity of the Gas shall be

determined at each point of measurement by continuous

sampler or other methods mutually agreeable to both parties.

3.6 Supercompressibility. The supercompressibility of the Gas

(deviation from the laws for ideal gases) shall be

determined by one of the following methods: