Horizontal Drilling: Overview of Geologic Aspects and Opportunities

STARK, PHILIP H., Petroleum Information Corporation, Denver, CO

Horizontal drilling and completions may become the most significant petroleum technology enhancement since reflection seismic. Through September 1990, 640 U.S. horizontal completions were recorded, resulting in 532 oil and 69 gas producers. In addition, 345 horizontal wells were drilling or completing and 255 permits were outstanding. More than 60% of historic US horizontal wells were completed during 1990. Case studies demonstrate higher production rates and improved recoveries for horizontal completions.

There are abundant global geologic opportunities for horizontal well technology. Eight geologic criteria with potential for horizontal technology are reviewed. Models and examples showing results are presented for each:

Source rocks--Bakken Shale case history, North Dakota

Fractured reservoirs--Austin Chalk case history, Texas

Paleokarst reservoirs--Liuhua field example, South China Sea, and karst reservoir potential, Mediterranean region

Chalk reservoirs--global distribution and Niobrara example, Colorado and Wyoming

Stratigraphic traps--Niagaran Reef example, Michigan basin, and tight, overpressured gas sands, northern Rocky Mountains

Reservoir heterogeneity--Spraberry trend example, Midland basin

Coal-bed methane--U.S. potential

Coning--Prudhoe Bay example, Alaska

Forecasts showing 5000 worldwide horizontal completions by the year 2000 are tempered by limited equipment, crews, and recognized opportunity. If, however, economic benefits from case histories are creatively applied to potential geologic opportunities, then horizontal technology may comprise 30% or more of worldwide drilling at the turn of the century. Certainly, a technology that reduces dry-hole and environmental risks, increases productivity, and generates profits with $20/bbl oil could revitalize the domestic onshore industry.

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