Russian researchers have developed a nondestructive method for testing drilling rigs and other equipment used in oil wells.
According to Peter the Great St. Petersburg Polytechnic University (SPbPU) researchers, the new process ensures efficient oil production and reduced time and cost of equipment repair.
Traditional nondestructive testing technologies are fast becoming ineffective for the diagnosis of modern structures made of corrosion-resistant and high-strength structural materials.
Moreover, conventional ultrasonic diagnostics fail to detect microcracks caused by metal fatigue which occurs during repeated loading and unloading of the structure.
At present, there is no effective method for nondestructive testing; the last major results in the field of nondestructive acoustic testing were obtained more than thirty years ago and were limited to the cases of elastic deformation of structures.
Now researchers led by Professors A. Belyaev and V. Polyansky, associate Professor A. Semenov and graduate student Dmitry Tretyakov, have developed an acoustoelasticity method to remedy the same.
The patented process combines mathematical models of fracture mechanics with the results of experimental measurements of ultrasonic wave velocities.
The method allows one to describe the effect of stresses, plastic deformations and systems of microcracks on the velocity of acoustic waves.
More importantly, the process also allows operators to give numerical estimates of damage throughout the structure.
The researchers contend that this mechanical stress monitoring system could be further extended to a wide class of deformation, leading to direct practical applications in the industry.
Going forward, Tretyakov and his fellow researchers will develop a new technology that can determine the internal structure of oil layers and the nature of its damage.
This technology will help predict the consequences of drilling and hydraulic fracturing, as well as provide an opportunity to diagnose working wells.
Image and content: Peter the Great St. Petersburg Polytechnic University (SPbPU)