DHV services are used mainly in cased-hole situations. The two major cased hole applications are for characterizing wellbore fluids, especially entry points, and for inspecting downhole mechanical equipment. Mechanical inspection can be used to:
In openhole wells, rock formations are easily viewed by the camera. However, when drilling mud is used, the mud is opaque and usually prohibits the use of a video camera
The Halliburton Fiber-Optic Camera System provides high-resolution, real-time visual examinations of downhole equipment, conditions and fluid flows at a wide range of pressures and at depths of approximately 16,000 feet, depending on deviation. Its fiber-optic telemetry system allows distortion-free transmission of clear, sharp images with signal quality that is 75 percent better than 7/16-in. coaxial cable systems.
A single electric conductor provides power and controls the camera and lights. A surface-based optical receiver decodes and sends the signal to surface equipment where the operator can monitor, record and produce a copy of the camera survey. Typically, we burn video data to a CD in a mpg format as well as recording it to a VHS tape.
The Halliburton HawkeyeTM camera system is a helicopter transportable video inspection system that operates on a conventional single or multi-conductor cable. The Hawkeye system is generally used when time is a critical factor or where corrosive fluids are present. The system utilizes many of the same downhole tools as the fiber-optic system and allows operators to view downhole conditions without a special coaxial or fiber-optic cable. Video images (or frames) are transmitted to the surface every 1.7 seconds over standard electric line logging cable. Complete redundancy for all mission critical components is provided along with rugged shipping containers for complete transportability.
An increasing number of wells are being completed in horizontal sections. To run through coiled tubing in these wells, Halliburton offers a combination of fiber-optic and conventional e-line technology. This method of transporting downhole cameras allows the Hawkeye camera system to be utilized in vertical, horizontal or highly deviated wellbore and at greater depths than was previously possible.