高温高压下矿物油泥浆和常规油包水乳化泥浆的流变性能

用 RheoChan 7400型高温高压旋转粘度计,全面测试了不同组成、不同比重的矿物油泥浆和常规油包水乳化泥浆(简称柴油泥浆)的高温高压流变性能。结果表明,当除基础油以外的其余组成相同时,矿物油泥浆的抗温能力和剪切稀释性能均优于柴油泥浆。试验还表明,这两类油包水乳化泥浆的表观粘度μ_a、塑性粘度μ_p和屈服值τ_0均随温度升高而降低,随压力增加而增大。常温时压力对μ_a和μ_p影响很大,但随温度升高压力的作用逐渐减小。在深部井段,影响油包水乳化泥浆流变性的主要因素是温度和泥浆的组成,而不是压力。温度对μ_a和μ_p的影响大于对τ_0的影响。

THE RHEOLOGICAL PROPERTIES OF MINERAL OIL AND DIESEL OIL MDDS AT HIGH TEMPERATURES AND HIGH PRESSURES (HTHP)

The HTHP rhcological properties of mineral oil muds and conventional invert emulsion muds (or simply diesel oil muds) with different compositions and densities were determined using a RheoChan Model 7400 viscometer. It was found that the temperature-resistant ability and shear thinning property of mineral oil muds are better than that of diesel based muds under the condition of the same composition except for base oils. The apparent viscosities., plastic viscosities and yield points of both invert emulsioti muds reduced with a rise in temperature, and rose with an increase in pressure. At a low temperature, the effect of pressure on the apparent viscosity and plastic viscosity was drastic. This effect, however, reduced gradually with the increase in temperature. The major factors affecting the rheological properties of the invert emulsion muds are the temperature and the composition of the muds, rather than the pressure. The effect of temperature on apparent viscosity and plastic viscosity was larger than that on yield point.