Introduction
This Open-File report builds on Carr and Gerlach (1997) in an attempt to develop a perspective on the trends in the relative importance of stripper well production to Kansas oil and gas production. Stripper wells are economically marginal oil and gas wells that produce at relatively low rates. The definition of stripper wells varies. For oil, stripper production is usually defined as production rates of between 5 and 15 barrels of oil per day (BOPD). Stripper gas production would generally be anything less than 90 thousand cubic feet per day (MCFPD).
Wells that are producing at stripper well rates make up a significant portion of Kansas oil and gas production, and more importantly represent a very large portion of existing well bores. These well bores represent a very large capital investment that is at risk of being plugged and abandoned.
Procedure
We examined the most recent available production data from the Kansas Department of Revenue from the period of January through May 1998. This provides a five-month period to average production and to capture leases that report production only on an intermittent basis. All leases that produced any oil or gas during the five-month period were extracted from the oil and gas production database. Lease production was divided by the number of wells listed for each lease and then by 150 days to obtain an estimated average daily production per well.
Results: Oil Production
Oil production in the first five months of 1998 was reported from 13,998
leases with 41,520 wells (Table 1a). The number
of leases is comparable to 1997 data (14,234 as reported by Carr and Gerlach,
1997). However, the number of oil wells is significantly higher in the present
study (41,520 compared to 31,691). This change in well number is the result
of different data sources. Commercial data were used in the 1997 Open-File
Report, while data from the Kansas Department of Revenue (DOR) are used
in the present study. Based on conversations with operators the DOR data
are believed to more accurately reflect the number of producing oil wells.
Total oil production in the first five months of 1998 was 15,117,274 barrels of oil (Table 1b). This is an average monthly production of 3,023,454 barrels of oil. Average daily per well production would be 2.4 barrels of oil. The reported 1998 production represents a 9.2% decline compared to the first five months of 1997.
The number of oil wells grouped by production rate shows that over 98% of the oil wells in Kansas average less than 15 BOPD (Table 1a). Approximately 40,829 wells producing 73.2% of the state's oil would be considered as stripper production. This represents a very large number of well bores that are at risk to abandonment. Comparing production rates and number of wells between 1998 and 1997 shows that there has been a significant decrease in the number of high production rate wells (> 30 BOPD) and there contribution to total production. The number of wells falling in the low production rate classes has increased. In part, this reflects the significant decrease in drilling and workover activity that can be attributed to the historically low Kansas oil prices.
Results: Gas Production
Gas production in the first five months of 1997 was reported from 15,059 leases with 17,780 wells (Table 2b). Total production was 238.1 billion cubic feet. This is an average monthly production of 47.6 billion cubic feet. Average daily per well production would be 90 MCF. The reported 1998 gas production represents a 17% decline compared to the first five months of 1997, and reflects production declines in the gas fields of southwest Kansas.
The number of gas wells grouped by production rate shows that 59% of the gas wells in Kansas average less than 90 MCFPD (Table 2a). Approximately 10,487 wells producing 17.8% of the state's gas would be considered as stripper production.
References Cited
Carr, Timothy R. and Paul M. Gerlach, 1997, Kansas oil and gas production: An examination of the importance of stripper production: Kansas Geological Survey Open-File Report 97-64, 4p.