Surveying Slim Hole Wells
A number of small MWDs and steering tools are available, mainly intended for the horizontal sidetrack market. There are a number of small gyros which were designed to be run through conventional drillpipe. Dip-meters can be used as surveying instruments.
Alternatives to surveying for cost-effective wells
For many cost-effective vertical wells, surveying the well to a “high” standards represents a significant proportion of the total well costs. The provision of surveying services, especially in remote areas, may outweigh the perceived benefits. For example, if the well is a rank wildcat . . .