Systems for automatic supply of surfactants as a tool for stabilizing production

Abstract

The article describes the study of the efficiency of automatic surfactant supply systems to substantiate the technological parameters of their use and optimise the operation of wells with high water cut. The objective of the study is to develop scientifically sound approaches to the selection and implementation of effective methods for removing fluid from the wellbore, taking into account their technical and operational parameters. The purpose of the study is to optimize technological parameters and select effective solutions for stable and uninterrupted supply of surfactants, which ensure increased productivity and reduced well operating costs. Calculations were performed to determine the minimum required gas flow rate, which showed that for none of the wells the condition of continuous fluid removal from the bottom is met. The minimum required gas flow rates, which are significantly higher than the actual flow rates, and the Froude parameters for gas and liquid flows, indicate this. Using the nomogram to select effective methods for intensifying fluid flow to the surface, it was concluded that the most optimal and effective method to counteract well watering would be an automatic surfactant supply system to the bottomhole zone. Further, laboratory tests of surfactant foaming agents of various modifications and concentrations were carried out. Namely: 1) studying the solubility (compatibility) of surfactants in the formation fluid; 2) comparative studies of the recovery capacity of the formation fluid with ‘SE’ type surfactants. The reservoir fluid from well M 226-Rudki was used as a sample. Studies on the selection of surfactants for the formation of foam with high foaming characteristics and the study of their recovery capacity were carried out on a reduced model well. The process of optimising the surfactant supply parameters includes the selection of such characteristics as flow rate, reagent consumption and surfactant concentration. The initial calculation was based on the actual gas velocity, which ranges from 0.89 to 1.29 m/s, and the minimum required gas velocity for stable operation and prevention of fluid accumulation in the wellbore, which ranges from 5.29 to 5.91 m/s. Based on laboratory studies of reservoir fluid and tests of the surfactant SE-235-A-S-30, the expediency of its use to increase the gas flow rate, which helps to stabilise well operations, has been substantiated. The industrial experience of well 226 at the Rudkivske gas field has shown that after the introduction of the technology for fluid recovery from the wellbore using an automatic surfactant supply system, the well began to operate stably. This ensures the complete removal of water from the wellbore and increases the well's flow rate by 22%.