In general, the key to determining the advantages of downhole video over more traditional surveys depends primarily on the nature of the problem and the cost differential. Another factor to consider is the time involved. Preparing the well and running the camera usually required an extra day of rig work. Overall, the strongest advantage of downhole video over traditional logging methods is the real-time nature of the system. The continuous feed allows the engineer and camera operator to analyze the data as it is obtained and to easily repeat the survey over sections of interest.
Mechanical Inspection. When it comers to casing inspection and detection of mechanical damage, the decision to use video relies primarily on the value of the information required. If the problem is a common field occurrence and other symptoms exist, it is often less expensive to run a simple mechanical profile log, or even an electro-magnetic casing inspection tool. However, if the nature of the damage is uncertain, running a video log often proves invaluable.
Fishing Operations. In fishing operations, if the initial attempt to remove the lost tool or item fails, running a camera often saves time, effort, and cost. In this case, removing the guesswork by obtaining an actual image of the lost fish and its orientation can easily save large amounts of money. Images can easily allow drilling and workover representatives to determine both the appropriate fishing tool and course of action. Overall, the use of downhole video can definitely save time and money.
Scale and Organic Buildup. For the detection and analysis of scale and organic buildup, the downhole video logs are unparalleled in the data they provide. Currently, there is no traditional, non-visual method for accurately assessing the amount of buildup and its impact on production. Using downhole video is a cost-effective and unique method for analyzing scale, paraffin, and asphaltene buildup. Downhole video can also be used to determine the effectiveness of various remedial procedures by imaging a well both before and after a treatment.
Sand/Particle Entry. Again, downhole video can provide images of sand and particle entry that would otherwise be undetectable using traditional logging methods. Images of sand entry usually show billowing clouds of fine particles flowing in through a slot or perforation. However, if the produced fluids are too opaque for imaging and the well requires clean fluid to be pumped down the annulus, this can make detection of sand entry a difficult proposition and subject to interpretation and general field knowledge.
Fluid Entry. For fluid entry surveys, traditional tracer and spinner surveys still compete with downhole video, especially if the produced fluid proves too opaque for clear imaging. In this case, the effort to provide a clean medium for imaging may prove too costly as well as hinder the natural flow of the well –leading to false data.
Overall, the downhole video system is superior to many traditional logging methods for mechanical inspection, fishing, and detection of scale and organic deposition. The only potential weakness is the cost and the need to prepare the well for imaging. This aside, obtaining a real-time visual image of the well remains a superior method of obtaining information.