A recent series of successful coiled tubing drilling (CTD) operations carried out in the Kansas Niobrara Formation in the United States demonstrates that CTD is about to be taken to the next level, according to a report from AnTech Ltd.

The drilling programme coincided with the launch of AnTech’s directional drilling services division, which further expands its capabilities beyond the company’s established design and manufacturing roots.

Hailed for being an efficient, safer and more environmentally-friendly means of drilling in shallow reserves and for re-entering existing wells, CTD has long been hampered by a way to drill 6-1/2 inch diameter directional wells without using an expensive rotary steerable. However, with the completion of the Niobrara drilling programme by AnTech and Advanced Drilling Technologies (ADT), an affordable alternative has proven to be a viable contender.Throughout the drilling programme AnTech’s new 5-inch POLARISTM tool performed extremely well, proving that it is capable of reliably drilling along a specific directional path.

The initial drilling programme consisted of drilling three wells along the Colarado - Kansas border. Armed with the POLARIS tool, the AnTech team worked in conjunction with ADT and one of its fleet of hybrid land rigs, which have proven to be extremely effective. In previous drilling operations, ADT have demonstrated that by using its hybrid drilling rig, drilling time can be reduced from seven to two days, when compared to operations carried out with a conventional jointed pipe rig. ADT has drilled more than 2000 vertical wells with CT, but the recent operations in Kansas were the first time that ADT had the opportunity to use the new POLARIS tool to drill directionally.

Responsive, steerable BHA performs

The first well to be drilled was an S-shaped directional well drilled to nearly 3000-ft. TVD and over 600-ft. lateral displacement. Following a one- day mobilization, the team carried out the second operation, a directional well drilled to over 1500-ft. TVD with an average dog leg severity of approximately 7.5°. Once again, the POLARIS was easy to steer, changing direction as intended and the job was completed in less than one day.

For the final well, the team travelled slightly south to the drilling site near Goodland, Kansas. The POLARIS drilled efficiently along the intended drilling path (over 1100-ft. TVD and 700-ft. lateral displacement). The operation was again completed on time, reconfirming the effectiveness of the solid state gyro system; the underlying technology that makes it possible to monitor orientation.

This revolutionary system removes the need for a magnetic steering instrument. This allows the tool to be very short, making it easy to steer. Because the sensors are very close to the bit, corrective actions are carried out immediately. As a result, the POLARIS tool can drill directionally from the casing to the end goal with great precision and cost efficiency.

Minimal environmental impact, maximum access

The directional capability and compact nature of the operations also combined to provide a solution with minimal impact on the environment, while providing access to places not feasible with vertical drilling. The wells were drilled under a river bed, under a hill and from the edge of a cornfield, without disrupting the ongoing harvest. They also took place in areas with no access road or prepared drill pads. Low margin operations of this type are only viable with a solution such as this, which can be mobilized quickly and efficiently, with rapid drilling operations.

For those seeking to access reserves in shallow depths, the ability of the POLARIS to accurately drill a path will come as welcome news. “Not only did the POLARIS perform as intended, all three operations were completed quickly, with minimal impact on the environment,” said Toni Miszewski, Managing Director of AnTech.

For ADT, the success of the POLARIS is especially meaningful. “Based on the success we have experienced using our hybrid rigs, we have always believed that an affordable, reliable downhole drilling system would revolutionise the directional market for CTD,” said Ovi Alfaro, President of Advanced Drilling Technologies. “Clearly, the Niobrara Formation operations prove that the POLARIS tool used in combination with our hybrid rigs will achieve that.”

Watch this space

The next two wells to be drilled by AnTech and ADT will demonstrate that the POLARIS can perform equally well when drilling horizontally, and under the harsher conditions of drilling with air.

“The success of these operations has shown that the POLARIS tool will most certainly be instrumental in catapulting the CTD market into new applications,” said Miszewski. “From simple shallow wells to multiple wells from a single pad, POLARIS offers a quick and cost-effective solution.”

The POLARIS is poised to unlock vast reserves in mature oilfields, as well as in untapped regions throughout the USA. The ability to monitor its orientation in the casing while drilling means that the POLARIS can effectively drill multiple wells from a single pad or sidetrack wells in older oilfields. Coupled with the fact that it is so easy to operate and quick to deploy and drill, it is set play a central role in the future of the oil and gas industry.

Tags: AnTech Limited