In retrospect of last decade improvement of oil and gas production is globally achieved using horizontal drilling and multi-stage fracturing.
With a general increase in the volume of drilling horizontal wells, the increase in the length of horizontal shafts and the number of MSF stages, the increase in oil production often does not correspond to the forecasted level, and one of the most important tasks of field development is to obtain the most complete information on the inflows of productive intervals of the wells
The conduct and interpretation of the results of the geophysical studies, that have proven themselves in vertical shafts in the horizontal wells are complicated by the multiphaseness of the flow, the changes in the velocity of fluid flow in wellbore, the presence of ascending and descending sections of the trajectory of the horizontal section of the well.
The direct transfer of the research technology and interpretation algorithms from vertical wells to horizontal wells is the cause of erroneous conclusions.
Production logging with markers detects intervals with good productivity as well as characterize the formation fluid.
The definition of the inflow profiles in well production is the basis for the adoption of technical decisions on the most efficient development of oil and gas fields, optimization of the solutions for well pumping or performance of the works on overhaul repair.
Until recently, there was no alternative to down-hole logging operations in the industry to determine: the locations of water inflow into the well, the position of the OWC and the control of its movement, the allocation of watered reservoirs, and the evaluation of enhanced oil recovery activities such as hydrochloric acid treatment or the multi-stage fracturing formation.
However, logging in a horizontal well is a relatively expensive procedure that requires the use of coiled tubing (CT) service or tractors. The feasibility and success of the operations depend on the seasonal availability of the well itself, the complexity of the shape and the intensity of the set of curvature at the sites and the locations of the changes in the internal diameter of the casing string.
In addition to such technical constraints, such as the need to stop well production, challenges to access the wellbore it provides downhole data during well intervention only.
However, they do not allow performing the long-time monitoring and to obtain a dynamic picture of production per interval. Moreover, well intervention is associated with the risks of stuck or loss of down-hole tools with subsequent costly fishing operations.
One of the alternative methods for well inflow profiles monitoring is the GEOSPLIT® technology, based on the use of markers-reporters® created from quantum dots.
The studies of the wells using marked proppant do not have the above limitations and allow increasing the efficiency of diagnostics of the inflows in the wells after MSF in the development of oil and gas fields.
The placement of markers-reporters® in the oil reservoir for a long-term period of time and their subsequent analysis on the surface after removal by the flow of the well fluid make it possible to bring the well management to a qualitatively new level.
The fundamental difference between this technology and conventional production logging is the ability to monitor production per interval for long period of time. The new approach causes drastic reduction in the resources involved as well as improve safety record.