Gardes Energy Services Inc
Gardes Energy Services, Inc.

The company that pioneered
multilateral drilling technology

Managed Pressure Drilling

High Temperature High Pressure (HT/HP) deep gas requires past technical obstacles be overcome with a more integrated approach to well control. Developments in underbalanced drilling technology have spawned new techniques and equipment for bottom hole circulating pressure (BHCP) control and hence well control. High pressure wells have traditionally been drilled with large over-balanced margins to minimize the risk of unplanned reservoir inflow. The high pressures associated with these influxes can result in large kick volumes, reduced reaction time and greater risk. Challenges associated with these narrow margins between equivalent circulating density (ECD) and frac gradient serve to increase loss circulation risk, resulting in high pressures, differential sticking and wellbore damage.

Technical obstacles for future HT/HP development:
a. Loss circulation/well control
b. Reduction in total time drilling/cost
c. Under formation pressure drilling for high pressure wells
d. Reducing formation damage
e. Horizontal and multi-lateral drilling

A new technique for dynamic well control addresses the need to control BGP quickly and accurately from the bottom of the wellbore and avoid the need for high surface pressure and time consuming increases in drilling fluid denisity. U.S. Patent 6,457,540 B2, foreign PCT filings pending titled "Method and System for Hydraulic Friction Controlled Drilling and Completing Geopressures Wells Utilizing Concetric Drill Strings" is a proven control of critical high pressure wells while drilling. It employs a combination of fluid injection down the drill pipe annulus and concentric casing annulus to create friction pressures on the return annulus and establish a desired ECD at depth to drill near balance, at balance or under-balanced in the formation. During connections, the normal standpipe injection colume is added to the normal annulus injection volume so the ECD remains constant, thus eliminating the bottom hole pressure surges associated with connections and minimizing connection gas influx.

The method employs a "continuous circulation system" and meets all the "technical obstacle requirements" previously listed. Average cost reduction in rig time saved could be as much as $1.0 million for an offshore well.