AAPG Methods in Exploration No. 14, Chapter 14: Cost-effective
Techniques for the Independent Producer to Identify Candidate Reservoirs for Horizontal
Drilling in Mature Oil and Gas Fields , by S.
Bhattacharya, P. M. Gerlach, and T. R. Carr, Pages 205 - 223
from:
AAPG Methods in Exploration No.
14: Horizontal Wells: Focus on the 
Reservoir
, Edited
by T. R. Carr, E. P. Mason, and C. T. Feazel
Copyright 
2003 by The American Association of Petroleum Geologists. All rights
reserved.
Chapter 14
Cost-effective Techniques for the Independent Producer to Identify Candidate
Reservoirs for Horizontal Drilling in Mature Oil and Gas Fields
S. Bhattacharya
P. M. Gerlach1
T. R. Carr
Kansas Geological Survey, University of Kansas
Lawrence, Kansas, U.S.A.
1Present affiliation: Charter Development Inc., Wichita,
Kansas, U.S.A.
ABSTRACT
Horizontal wells have exploited successfully the remaining oil potential in mature
reservoirs around the world. Because a typical horizontal well costs 1.3 to 4 times that
of a vertical well, it must produce significantly greater volumes of oil to be considered
an economic success. Previous studies have concluded that poor selection of target
reservoirs has been the principal cause of failure of horizontal wells. Many mature fields
in the Midcontinent of the United States have significant volumes of residual reserves,
and vertical wells have proved to be uneconomic for producing these unswept assets. Small
independent producers with limited financial and technological resources operate most of
these fields. In Kansas, few horizontal infill wells have been drilled, and results have
been mixed. Operator concerns for an appropriate economic return and the difficulty in
cost-effectively identifying candidate reservoirs have restricted application of
horizontal-drilling technology in many mature production areas of the Midcontinent.
