Total: Successful Radial Cutting Torch Application in Russia

Weatherford, which specialists successfully completed complex interventions in severe High North environment, is successfully operating with major Russian and foreign operators at the oil fields of the Timan-Pechora Province, Komi Republic, as well as Nenets and Yamal and Nenents Autonomous Areas.

Various mills, cutters, perforators and dressing tools, etc. are usually used for complex fishing operations. But the recently introduced RCT™* radial cutting torch proved to be reliable and now it is used widely all over the world. It should be noted that efficiency of this innovative tool was proven several times at hard to develop fields in the north of Russia.

The torch is designed for cutting of various tubing strings (tubing), coiled tubing, casing and drill pipes in any conditions of drilling, completion and well stimulation. It is one of the safest tools that are available for cutting of pipes. At the same time it provides a clean cut at the exact depth and eliminates the need for explosives or highly toxic chemicals. It can cope with any pipe types made of conventional or special materials. The radial cutting torch is as efficient as the acid cutting tool. At the same time it uses a special powder mixture of metals instead of hazardous chemicals. Using a front-edge technology, the mixture is ignited and a strong flow of high energy plasma is directed through nozzles of the cutter to the object, which has to be cut (pipe). The principle is quite similar to gas cutting and takes 25 ms only.

Successful Radial Cutting Torch Application in Russia

In 2013, a radial cutting torch with a perforating torch cutter was used at a field of Novy Urengoy, which resulted in re-establishment of wellbore circulation and cutting of stuck tubing. Thus NPT was reduced and operational safety was improved. RCT was used to cut and retrieve tubing stuck during multistage well test operations in an exploration well located inside the Polar Circle.

The operator has tried to release the stuck string, but the heavy mud weight prevented the release. It was critical to reduce non-productive time (NPT) and re-establish wellbore circulation. The barite based mud in the well created a high bottomhole pressure of 97.2 MPa.

To expedite the tubing recovery using assets within the country and to test the new product, the operator decided to use the radial cutting torch (RCT) rated for 68.9 MPa. Wireline Logging specialists deployed a 1.688-in. perforating torch cutter (PTС™*) tool to punch the drill pipe at 3,500 m and establish a circulation vent in the coil for the cutter run. After the mud was substituted and pressure reduced to 65.8 MPa, the RCT tool successfully cut the drill pipe in one run and a good indication of the cut was observed immediately on the surface. Moreover the tool eliminated the need for explosives used in alternative methods. Thus the operation was completed promptly and safely for both personnel and the environment. After a clean cut at the exact depth, the drill pipe was released. The cut end was not collapsed and had the original outside diameter. It was ready for fishing operations with minimal lost time.

Generally the use of the tool provided a safe and effective solution with no hazardous chemicals or explosives, greatly enhancing the safety of the operation and well operations resumed quickly saving significant NPT. It should be noted, that similar operations were carried out at the field several times and all these operations were successful.

Unique operation for a packer release

In 2014, Total E&P Russie, an affiliate of TOTAL SA petroleum company operating, at the Kharyaga field, decided to work over a well that is located north of Usinsk. One part of the intervention was aimed to pull and replace the existing completion string. In order to retrieve the string, a 7-inch permanent completion packer had to be pulled out from 2,000 m. To achieve it, a 30-cm inner sleeve located inside the packer body had to be cut.

It should be noted that generally chemical cutters are used for such operations. However the use of such cutters is limited in Russia as some chemicals, which are used in them, are either prohibited for import to Russia or their transportation is quite difficult. Due to customs and logistics constraints, a solution had to be found and an alternative process for pup joint cutting had to be selected. Total E&P Russie consulted major service companies in order to assess the most reliable solution for the scope of work. Among the tools available in Russia, the operator selected Weatherford Radial Cutting Torch as a primary and a mechanical cutter as a contingency. Coordination of the service companies involved and good job preparation had been key points to cut of the 30-cm pup joint inner sleeve successfully at a significant depth. It should be noted that such operations to release packers (not pipes) with the use of a radial cutting torch had never been done in Russia before but both Total SA and Weatherford experiences from other affiliates improved preparation. Finally the packer was released in time and the string was retrieved to the surface. Due to the use of the radial cutting torch the cut itself was made precisely at the selected depth with no complications and in one trip. The Customer was very pleased and satisfied with the work.

Generally, representatives of Weatherford and several customers, who have tried this innovative tool in practice believe, that the tool has good perspectives in Russia as it can be used efficiently, promptly and safely in many complex interventions.

Authors: Sergey Borisenko, Sergey Turlayev (Weatherford) and Paul Peyrucq (Total)

**RCT™ and PTC™ are trademarks of MCR Oil Tools used by Weatherford under the license granted by MCR Oil Tools, LLC.