Emphasis on 5,000-20,000 ft exploratory objectives offshore and on land in the U.S. in 1994 resulted in the highest average depth per well ever, 6,079 ft, a multiassociation survey shows.
This emphasis also resulted in both the highest average cost per well, $483,237, and second highest average cost per foot, $79.49, in more than a decade.
The Joint Association Survey on Drilling Costs is available from the American Petroleum Institute, Washington, D.C. The JAS is published by API, Independent Petroleum Association of America, and Mid-Continent Oil & Gas Association.
The 1994 well costs are extrapolated from voluntary responses from 900 operators out of 3,026 surveyed. The respondents operated 43% of the estimated 20,023 well completions in the 1994 JAS universe.
The survey
The surveyors use regression analysis to model costs for nonreported wells as a function of their depth, type, and general location.
The survey lists well cost data by state and depth range, including land and offshore. It has breakouts for horizontal and coalbed methane wells, and nationwide summaries of the costs of exploratory and development wells, single and multiple completions.
Operators report a total cost that generally includes all expenditures for drilling and equipping wells, including dry holes, through the christmas tree.
A small sample of individual categories by state and depth range, with cost per foot calculated by OGJ, is reproduced here (see table). Sample costs for 1991-92 were published earlier (OGJ, May 16, 1994, p. 70).
Horizontal wells
JAS tabulated 893 horizontal wells in 1994 costing a combined $1.012 billion.
Horizontal wells' average cost was $1,133,609, and average cost per foot was $98.48. Average distance (measured depth) drilled was 11,511 ft, more than twice that for wells not drilled horizontally.
For all wells not drilled horizontally, average cost was $452,877/well, average cost per foot was $77.74/ft, and average measured depth was 5,826 ft.
The largest group of horizontal wells, 605 wells in Texas Gulf Coast Dist. 3, averaged 13,018 ft measured depth and cost an average $98.57/ft.
North Dakota had 20 horizontal wells that averaged 9,953 ft in measured depth and averaged $68.96/ft.
East Central California had 16 horizontal wells that averaged 6,402 ft in measured depth and cost an average $153.90/ft.
Coalbed methane wells
JAS measured 238 coalbed methane wells in 1994, of which 211 were completed as gas producing wells.
The 211 CBM wells that produced cost a combined $37.379 million.
Fifty-two CBM gas wells in Virginia averaged 2,240 ft in depth and cost $79.06/ft.
Forty-nine CBM gas wells in Alabama averaged 2,681 ft in depth and cost $51.03/ft.
Thirty CBM gas wells in Utah averaged 2,492 ft in depth and cost $98.88/ft.
Thirty CBM gas wells in Oklahoma averaged 1,509 ft in depth and cost $37.49/ft.
Some 97% of all CBM gas wells were drilled to 200-5,000 ft. The average cost per foot for these wells was $69.96, comparaed with the $49.56 average cost per foot for all other gas wells drilled at the same depth range.
Copyright 1996 Oil & Gas Journal. All Rights Reserved.
