The newly developed electric drive rope winch by ZOLLERN is employed for the first time as part of a highly sophisticated mobile drilling system used to drill down to a depth of 5 kilometres for gas resources.
For the first time, ZOLLERN uses an asynchronous motor developed inhouse and specially designed to meet the performance requirements of the rope winch. By including their own drive unit and gearbox, ZOLLERN are ensuring that all the core components for the new compact electric winch will be provided by the expertise of the Group and are thereby enabling customised solutions for special customer applications.
In the future, special drilling rigs are to be used in Russia to exploit natural gas deposits. These will enable drilling to a depth of 5,000 metres at temperatures down to minus 40 °C. The special features of these drilling rigs are their mobility and the associated rapid availability for use. To achieve this, the entire drilling rig with its 30-metre swivel tower, rope winch and drilling unit are integrated into a vehicle that can reach the appropriate drilling sites in a short period of time. The drill, fed from a store of 150 individual drill rods according to drilling depth, is moved vertically via the raised derrick and set to rotate by a drill drive unit.
This extremely demanding application sees the first use of an electric rope winch from the new ZOLLERN series, where the entire drive train, consisting of an asynchro-nous motor and planetary gear, has been integrated into the inside of the rope drum. The 340 kilowatt, oil-cooled motor has been developed and produced in-house, as has the two-stage planetary gear. Both components have been adjusted seamlessly one to the other and optimised for this application. They ultimately exert a cable pull on the drum of 160 kN and a maximum speed of 600 m/min. An additional hydraulic emergency drive with two spur wheel gear stages will ensure that, if the main drive unit were to fail, the drill system can be drawn out of the drill hole to prevent damage. Peter Berger, designer of the new rope winch, stresses that “This first application of our new series of electric winches demanded everything from us. Because it is mounted on the vehicle, it was impossible for the winch to be even 10 millimetres wider, so we had to optimise every single detail. We had to carry out this space-saving optimisation keeping the demand for protection from explosion accidents in mind.” The requirement for protection from explosion accidents, for which the final approval is issued by the TÜV [Technischer Überwachungsverein, German Technical Inspection Authority], is due to the high risk of explosion in gas drilling. To implement this demand, all heat-producing components had to be in an enclosed capsule design. Even braking temperatures could not exceed 200 °C.
Ulrich Niele, managing director of the project developer delta P GmbH , gives the following reasons for this first use of an electrically driven rope winch: “In this perfor-mance class and under these operating conditions, we would most probably have had problems with control of the hydraulics. Also, we have repeatedly observed that in Russia the attention paid to hydraulic systems during maintenance is not particularly outstanding, which can lead to more frequent malfunctions. We therefore find the new ZOLLERN system very convenient.”
[mappress] LNG World News Staff, June 07, 2012; Image: zollern