Investigating drilling fluid formulations to penetrate productive horizons with high-viscosity formation fluids

Abstract

It draws our attention to the processes of interaction between the well and the penetrated permeable formations during its construction, which are largely determined by geological and thermobaric conditions, types of fluid saturating the formation, used technologies and technical means. The article deals with the main problems of well construction intended for the high-viscosity oil production. Laboratory and experimental studies have been conducted to solve these issues, they will help to scientifically substantiate and implement new technologies and technical means to increase productivity and durability of wells intended for production of high-viscosity oil from productive formations with complex thermobaric conditions. In this work, the authors conducted a study of the formulations of flushing fluids to penetrate productive horizons with high-viscosity formation fluids. Based on the results of the laboratory tests, it was decided to use a fresh polycationic solution.

Improvement of the well cementing technology

“…The conducted set of experiments and the analysis of scientific and technical literature made it possible to develop an algorithm for creating excess pressure in the annular space, included in the Measures developed by JSC "SevKavNIPIgaz" to improve the quality of well cementing. Since 2009, these Measures have been successfully implemented in the cementing of production strings of high-performance wells of the Nevsky UGS [9], which…”

“…It has been established that when the BHZ is chemically fixed with binders, the pore space interval is partially filled with hardening products and the reservoir permeability decreases. In this regard, when strengthening the cemented sandstone of the flooded BHZ interval, an important criterion for optimizing the strengthening is not only to ensure the strength of sand fixation, but also to maintain the filtration characteristics of the treated interval [1,2].…”

Improvement of the well cementing technology, increasing the reliability of the annule isolation and preserving the permeability of the reservoir

“…The conducted set of experiments and the analysis of scientific and technical literature made it possible to develop an algorithm for creating excess pressure in the annular space, included in the Measures developed by JSC "SevKavNIPIgaz" to improve the quality of well cementing. Since 2009, these Measures have been successfully implemented in the cementing of production strings of high-performance wells of the Nevsky UGS [7], which was reflected in their use in the development of the normative document Recommendation Gazprom.…”

“…It has been established that when the BHZ is chemically fixed with binders, the pore space interval is partially filled with hardening products and the reservoir permeability decreases. In this regard, when strengthening the cemented sandstone of the flooded BHZ interval, an important criterion for optimizing the strengthening is not only to ensure the strength of sand fixation, but also to maintain the filtration characteristics of the treated interval [8,9].…”