NATURAL GAS SUPPLY ASSOCIATION

Reasons for the Survey

The NGSA Deliverability Survey measures the difference between producers' ability to deliver gas into the transmission system and their actual deliveries. It was initiated in the mid-1980s to provide statistical support for the effort of many gas producers to better manage inventories to alleviate the negative effects of what was then a significant surplus of natural gas in the marketplace.

Survey Regions

The Survey collect data on the following supply basins:

• Offshore Gulf of Mexico.
• Onshore Gulf of Mexico.
• Permian Basin.
• San Juan Basin.
• Anadarko Basin.
• East/North Central (Appalachia) Basin.
• Rocky Mountain/Pacific Basin.

Measurements

The following measures are reported on both an annual calendar basis and a month-of-December basis:

• Connected capacity: The volume of wellhead gas that can be physically injected into the gas transmission system on a thirty day sustainable basis.
• Capacity utilization: The percentage of connected capacity used to actually deliver gas over some period of time.
• Maximum feasible capacity: An estimate of the percent of time that a gas field cannot produce at its sustainable rate due to these other factors. Capacity utilization, in conjunction with the maximum feasible capacity factor, provides a picture of how close wellhead capacity is operating to its practical limits.
• Unconnected capacity: Productive capacity that could be made available in a one-year period due to the upgrading or installation of new production infrastructure. Unconnected capacity typically refers to productive capacity that is either not connected to the transmission system or is unavailable for delivery due to gathering or processing bottlenecks.

Other Important Aspects of the Survey

• Each year's Survey measures capacity utilization for two years in succession. Thus, each survey provides two data points that provide an unambiguous trend line; the bias created by an ever-changing pool of survey respondents is thus eliminated. Moreover, each survey data point overlaps with the data points provided by prior and subsequent surveys. This provides a consistency check between surveys.
• Survey results, available for every year following 1990, show producer success in shrinking unneeded surpluses. There has also been a trend toward increased maximum feasible capacity estimates.
• Survey results reinforce the general industry perception that gas producers have employed advanced technology and management techniques to obtain higher production levels at the lowest possible cost.
• An almost perfect linear correlation has been found to exist between the Survey's annual capacity utilization levels and the reserve-to-production ratios calculated from the Energy Information Administration data on natural gas production and reserves.

This page was placed October 6, 1996; last updated August 31, 1997.