Geological Controls on Variable Character of Arbuckle Reservoirs in Kansas: An Emerging Picture

Evan K. Franseen, Alan P. Byrnes, Jason R. Cansler*, D. Mark Steinhauff**,
Timothy R. Carr, and Martin K. Dubois

Kansas Geological Survey, The University of Kansas
(*Present Address: ChevronTexaco; **Present Address: ExxonMobil Exploration Company)

Introduction

Since the 1910’s, several billion barrels of oil have been produced from the Central Kansas Uplift (CKU), primarily from carbonate reservoirs within the Arbuckle and Lansing-Kansas City groups. The majority of Arbuckle reservoirs of central Kansas were drilled prior to 1955 and constitute a series of giant and near giant oil fields (Figure 1). The significance of the Arbuckle to Kansas production and reserves is highlighted by the estimate that Arbuckle reservoirs have produced about 2.19 billion barrels of oil (BBO) representing approximately 36% of the 6.1 BBO of total Kansas oil production to date (Figure 2). Arbuckle lease oil production is log-linearly distributed with nearly 50% of all production produced by 6% of all leases and approximately 80% produced from 20% of all leases (Figure 3). This lopsided distribution of Arbuckle lease productivity is typical of complex natural phenomena. Arbuckle reservoirs produce from 31 counties statewide with a significant portion of the total production coming from the 10 counties in the CKU region (Figure 4). Within the ten county area on the CKU, the Arbuckle has produced over 1,630 MBO, representing 69% of the production from the top four producing intervals in this region (Figure 5). Table 1 lists the 21 most productive Arbuckle fields and the cumulative oil production attributed to each. These fields represent approximately 56% of all Arbuckle production with nineteen of the fields lying on the CKU and the remaining two on the Nemaha Uplift in Butler and Cowley counties. Although the Arbuckle has been a prolific producing interval since 1917, annual production peaked in the early 1950’s at more than 68 million barrels and has declined to approximately 12 million barrels per year in 2002 (Figure 6). Today, stripper production dominates Arbuckle production with over 90% of wells producing less than 5 barrels of oil per day and is very sensitive to commodity prices.

The long production history and exploration/exploitation strategies have led to some commonly held perceptions about Arbuckle reservoir properties. These include: