DTD recently completed a biosparge well in Colorado to block the downgradient movement of residual contaminants from a decommissioned gas station. The 400 foot, double ended well was completed primarily in shale, one of the sub-members of the Mancos shale formation which is widespread in the region.
Despite its relative lack of induration, shale can be tricky to drill with directional bits. Rock drill bits can be difficult to control in pitch or azimuth in soft rock, due to the softening effect of the water jets in the bit, which counteract the cutting/steering action of the bit teeth. Softer formation bits may steer better, but penetration rates are often slow. Sometimes experimentation is required to find the right combination of bit, technique, and drilling fluid pressures to successfully complete the well.
This biosparge well was completed within a slightly extended time frame, working with the client to maintain an acceptable bore path for them to complete pilot testing. The rest of the treatment system will be installed shortly, with operation of the system slated for startup in early 2013.
For more information on this project, or to discuss a project of your own, call DTD at 800-239-5950, or contact Mike Lubrecht directly at [email protected]