论文部分内容阅读
固井作业的失败25%表现为气窜。因此,人们开展研究,对水泥浆的各种性质,如失水量、渗透性、静胶凝强度及其他一些性质进行评价。然而对这些可变量的研究并没有得出防范气窜以及对水泥浆哪些性质的控制能避免这样问题的方法。本文描述了一种控制气窜的方法,研究结果得到了现场实验的验证。该方法包括三个步骤:首先是评价窜流潜能因子(FPF),这是一个预测问题严重程度的参数;然后测量随时间变化的静胶凝强度,得到水泥浆的过渡时间;最后,在窜流分析仪(FMA)上模拟静胶凝强度造成的压力降随时间的变化,从而确定水泥浆是否被气侵。在委内瑞拉东部的SantaBarbara和SanJoaquin油田现场实验了3口井。在每口井中,用气层孔隙压力、温度、气层深度及穿过气层的环空尺寸来确定窜流潜能因子的大小。室内研究与现场实验结果一致,室内实验是以对水泥浆过渡时间及窜流潜能因子的定量测量为基础的。应用这种方法可以对水泥浆进行优化设计从而防止生产事故的发生,确保油井的使用寿命。
25% failure of cementing operations showed gas channeling. Therefore, research was conducted to evaluate various properties of the grout, such as water loss, permeability, static gelling strength, and other properties. However, there is no way to avoid these problems by controlling these variables and preventing the gas channeling and controlling the properties of grout. In this paper, a method of controlling gas channeling is described. The research results are verified by field experiments. The method consists of three steps: first, to evaluate the cross-flow potential factor (FPF), which is a parameter that predicts the severity of the problem; then measure the static gelling strength as a function of time to get the slurry transition time; and finally, The flow analyzer (FMA) simulates the pressure drop over time due to the static gel strength to determine if the grout is being pneumatically intruded. Three wells were tested at the Santa Barbara and San Joaoquine fields in eastern Venezuela. In each well, the pore-formation pressure, temperature, depth of the gas layer and annulus size across the gas layer are used to determine the size of the cross-flow potential factor. Laboratory studies are consistent with field experiments, and laboratory experiments are based on quantitative measurements of cement slurry transit time and cross-flow potential factors. This method can be used to optimize the design of cement slurry to prevent the occurrence of production accidents and ensure the service life of oil wells.