TO THE ISSUE OF LIGHT ALLOY DRILL PIPE DESTRUCTION

Abstract

The almost ubiquitous complication of drilling conditions led to increase drilling depth, namely longest measured depth extended-reach drilling wells. The use of combination drilling becomes more relevant. The total weight of the used drill string acquires an important role, since depending on the weight friction and wear of the string against the borehole wall, as well as the general stress-strain state of the drill string increase. An important aspect in this issue is to ensure reliable operation of the drill string, which is used in extreme conditions of temperatures and loads. The latter significantly affects the technical and economic parameters of the drilling well. At the same time, certain restrictions are imposed on the material selection for drilling equipment and the safety factor for tensile/compression of drill string. The solution to the problem of optimizing the drilling process is reduced to the use of not only high-speed drilling methods and rock-cutting tools modernization, but the aluminum drill pipes inclusion in the composition of the combination drill string. Light-alloy drill pipes and the material of aluminum alloys from which they are made have a number of advantages in physical, mechanical and strength properties that distinguish them from steel drill pipes, S-135 and G marks. Almost 3 times the specific gravity and modulus of elasticity of aluminum alloys exceeds and the specific strength is 1.5-2 times. The efficiency of using aluminum drill pipes directly depends on the properties of aluminum alloys and makes it possible to exclude corrosive activity in aggressive environments during the drilling process, also to ensure the best outgoing capacity of the sludge to the surface due to minimal hydraulic losses in the well circulation system. In this paper, the possibility of increasing the mechanical properties of LADPs by the method of severe plastic deformation is considered.