Development of a High Temperature and High Pressure Oil-Based Drilling Fluid Emulsion Stability Tester

Huaiyuan Long,Dichen Tan,Wu Chen,Shunyuan Zhang,Song Wang,Lanping Yang

doi:10.4236/ojogas.2021.62003

Abstract

When drilling deep wells and ultra-deep wells, the downhole high temperature and high pressure environment will affect the emulsion stability of oil-based drilling fluids. Moreover, neither the demulsification voltage method nor the centrifugal method currently used to evaluate the stability of oil-based drilling fluids can reflect the emulsification stability of drilling fluids under high temperature and high pressure on site. Therefore, a high-temperature and high-pressure oil-based drilling fluid emulsion stability evaluation instrument is studied, which is mainly composed of a high-temperature autoclave body, a test electrode, a temperature control system, a pressure control system, and a test system. The stability test results of the instrument show that the instrument can achieve stable testing and the test data has high reliability. This instrument is used to analyze the factors affecting the emulsion stability of oil-based drilling fluids. The experimental results show that under the same conditions, the higher the stirring speed, the better the emulsion stability of the drilling fluid; the longer the stirring time, the better the emulsion stability of the drilling fluid; the greater the oil-water ratio, the better the emulsion stability of the drilling fluid. And the test results of the emulsification stability of oil-based drilling fluids at high temperature and high pressure show that under the same pressure, as the temperature rises, the emulsion stability of oil-based drilling fluids is significantly reduced; at the same temperature, the With the increase in pressure, the emulsion stability of oil-based drilling fluids is in a downward trend, but the decline is not large. Relatively speaking, the influence of temperature on the emulsion stability of oil-based drilling fluids is greater than that of pressure.

Highlights

With the continuous development of international petroleum exploration and development technologies, the deeper and deeper the well is, the more difficult it is to explore and develop oil and gas
A high-temperature and high-pressure oil-based drilling fluid emulsion stability evaluation instrument is studied, which is mainly composed of a high-temperature autoclave body, a test electrode, a temperature control system, a pressure control system, and a test system
The test results of the emulsification stability of oil-based drilling fluids at high temperature and high pressure show that under the same pressure, as the temperature rises, the emulsion stability of oil-based drilling fluids is significantly reduced; at the same temperature, the With the increase in pressure, the emulsion stability of oil-based drilling fluids is in a downward trend, but the decline is not large

Summary

Introduction

With the continuous development of international petroleum exploration and development technologies, the deeper and deeper the well is, the more difficult it is to explore and develop oil and gas. Oil-based drilling fluid is a dispersion system with water droplets as the dispersed phase and oil (diesel or mineral oil) as the continuous phase. The emulsion stability of oil-based drilling fluids directly affects the performance of the drilling fluid, which is one of the core issues of drilling fluid research. When drilling deep wells and ultra-deep wells, the downhole high temperature and high pressure environment will destroy the performance of the drilling fluid, thereby affecting the emulsion stability of the drilling fluid. It is very important to develop an oil-based drilling fluid emulsion stability tester under high temperature and high pressure conditions and establish an evaluation method [1]-[6]

Methods

Results

Conclusion