THE EFFECT OF PLANT COLMATANTS ON THE PROPERTIES OF FOAM SOLUTIONS FOR SILENCING WELLS AT ALRP (abnormally low reservoir pressures)

Abstract

One of the key problems during workover operations in conditions of abnormally low formation pressure (ALFP) is the loss of technological fluids and, as a consequence, deterioration of the reservoir filtration-capacitive properties. The use of foam solutions allows minimizing repression on the formation, but to ensure temporary blocking of the productive horizon for the repair period, it is necessary to increase the stability and structural strength of the foam. This paper investigates the possibility of increasing the blocking ability of foam polymer solutions (FPS) by introducing plant-based bridging agents. In laboratory conditions, the effect of additives of crushed straw, nutshells and cotton husk on the foam quality, stability and heat resistance of FPS was studied. It was found that the optimal fillers are crushed straw and nutshells, providing foam stability up to 7 days while maintaining its structural integrity. It has been experimentally proven that replacing liquid glass with NaCl (concentration 2% selected experimentally as optimal) allows achieving maximum long-term stability of the solution. Using sand-packed models of the reservoir, it was proved that the presence of plant bridging agents in the FPS composition reduces the depth of filtrate penetration by 2-3 times compared to the composition without filler, forming a thin but strong bridging cake on the surface. The research results were confirmed by industrial tests at wells of the Yolguyy and Garashsyzlygyn 10-yyllygy fields, where the use of the developed compositions made it possible to restore well productivity and increase gas flow rate.