GAMMA AND ELECTRO-LOGGING DURING WELL WORKOVER USING THE TECHNOLOGY OF RADIAL BRANCHING OF FORMATION

Abstract

The efficiency of oil recovery from oil-bearing reservoirs by modern, Abstract. industrially developed development methods in most oil-producing countries today is considered unsatisfactory, and the final oil recovery of reservoirs in various countries and regions averages from 25 to 40 %. For example, in Latin America and Southeast Asia, average oil recovery is 24–27 %, in Iran — 16–17 %, in the USA, Canada and Saudi Arabia — 33–37 %, in the CIS countries and Russia — up to 40 %, depending on the structure of oil reserves and the development methods used [1].Therefore, the task of managing the productivity of oil and gas reservoirs remains relevant at present.The article discusses a special technology for the use of gamma and electro-logging as part of the Perfobur technical system (hereinafter referred to as pyrolysis oil). These geophysical methods of investigation, at the end of drilling radial channels over a small diameter and radius of curvature, performed with trajectory control, make it possible to prove that drilling was carried out in a given reservoir, and provide more detailed information about its productivity.One of the areas of use of pyrolysis oil is enhanced oil recovery, intensification of inflow, restoration of normal operation of wells stopped or hindered due to falling at the bottom of oil field equipment, blocking or contamination of the perforation zone, including during initial penetration [2–5].Complex geological conditions are noted, such as high reservoir fragmentation, heterogeneity of the carbonate reservoir, fracturing, large lateral permeability variability, high oil viscosity and presence of washed zones, caverns after salt-acid treatment (SW) with subsequent steam injection. Under such conditions, it is difficult to develop a field, new well logging methods are required, as well as high-quality logging to determine saturated interbeds. Effective development of the field requires the determination of the current reservoir saturation with higher accuracy, which will help the subsoil user to better develop the field, eliminate stimulation of watered beds, and carry out better and more selective intensification of interbeds. It should be noted that the presence of a steel column practically eliminates the possibility of using electrical logging methods. Therefore, it is recommended to use such methods in an open hole. Drilling of radial channels using the Perfobur technology allows electro-logging with a special tool due to the possibility of repeated entries into the drilled channels [2–5].