In today’s operations in the conditions of drilling technologies active development, well completion and production intensification, there is a tendency towards increasing growth lengths of horizontal sections of horizontal drilling volumes, resulting in an increase of multi-zone hydraulic fracturing stages.
With existing conventional horizontal well logging methods, alternative technologies that utilize tracer-based inflow indicators are becoming more common. These technologies enable horizontal well production logging and allow users to obtain long-term analytical information.
The objective of this article is to analyze the efficiency of several production logging methods applied to horizontal wells with multi-stage hydraulic fracturing at Sredne-Nazymskoye field.
During the project, horizontal well oil and water inflows were monitored using a 15-stage hydraulic fracturing and the application of marked polymer-coated proppant. Monodisperse polymer microglobules, encoded for each stage of the multi-stage hydraulic fracturing and interacting selectively with water and oil, were used as markers. Upon completion of the stimulation works and once the well was put into operation, formation fluid sampling from the wellhead was carried out with subsequent analysis to determine the concentration of markers of each code and was associated with fracturing stages.
Well production logging with the marked proppant application was carried out periodically for several months, and the horizontal well profiles were built on the basis of the obtained analytical data. The results allowed us to conduct a long-term analysis of the stimulation efficiency for each of the hydraulic fracturing stages. We also used the data to assess the formation reserves development for each of the multi-stage hydraulic fracturing stages.
In contrast to conventional logging methods, the primary advantage of the horizontal well production logging technology is that there is no requirement to use special means of tool deliver and there is no risk of down-hole tools getting stuck or a loss or ambiguity of interpretation.
During the course of the study, the performance of the monitoring technology was confirmed using flow indicators placed in the hydraulic fractures, providing long-term selective interaction of marker particles with water and oil parts of formation fluid. The obtained geological and technical information contributes to further planning of effective geological and technical measures and additional oil recovery.