An Analysis of the Kansas Hugoton Infill Drilling Program

MCCOY, THOMAS F., Phillips Petroleum Company, Bartlesville, OK

This work compares the performance of the infill wells drilled in the Kansas Hugoton to the companion original wells using official deliverability tests and historical production. In addition, the performance of five experimental replacement wells drilled in 1977 in the Kansas Hugoton are compared to the performance of the infill wells. In this experiment, the original wells were shut in and used as observation wells for 10 years with wellhead shut-in pressures taken monthly. The average infill well (drilled between 1987 and 1989) had an initial wellhead shut-in pressure that was 300 psi less than the initial field discovery pressure of 450 psia (1930), indicating significant drainage of gas in the area of every new infill well. The average initial wellhead

shut-in pressure of the infill wells was 14 psi higher than the companion original wells. This pressure difference does not reflect any additional gas in place but is a result of the pressure gradient caused by flow toward the original well. Differences in official deliverability (used to calculate allowables) between the infill and original wells are shown to be unreliable indicators of additional gas in place. On average, the infill wells are not able to reproduce the quality of the stimulation jobs found in the original wells. The comparisons presented in this work indicate that the infill wells have not found any evidence of additional gas in place.

AAPG Search and Discovery Article #91008©1991 AAPG Mid-Continent Section Meeting, Kansas Geological Society, Wichita Kansas, September 22-24, 1991 (2009)