水基泡沫钻井液稳定性影响因素分析

发布时间：2018-10-14 17:16

【摘要】：泡沫钻井液作为欠平衡钻井液的一种主要类型,有较多优势:钻速快、对地层伤害小、悬浮能量强、有效的保护钻具及钻头等。评价泡沫钻井液好坏最首要的是发泡性能与稳泡性能,其中稳定性能直接影响钻井工程是否能顺利进行。目前已有较多学者对泡沫的稳定性方面进行了研究,但一般为单一的排液或单一的气体扩散的数学方程分析,较少系统的将二者进行分析,针对此问题,本文对水基泡沫的稳定性影响因素及性能评价在宏观及微观上进行了分析,同时进行了泡沫排液和气体扩散系数的数学方程分析。本文开展的主要工作如下:首先通过对八种不同种类发泡剂的发泡性能和稳泡性能评价,筛选出发泡高度为780mL,半衰期为605s的发泡剂YLB,并利用体式显微镜和Nano Measure 1.2软件对发泡剂YLB和发泡剂K12进行了微观对比分析,得出发泡剂K12粒径大小分布为56.49～540.35μm,平均粒径高达246.94μm;发泡剂YLB粒径大小分布为29.38～260.72μm,平均粒径为86.29μm,从微观上分析证明了发泡剂YLB的稳定性能较好。其次在室内考察了发泡剂YLB在不同的影响因素下(如:浓度、温度、基液黏度、无机盐含量与pH值等)泡沫的稳定性能。同时运用Scion Image软件在不同的浓度、温度、时间、PH值条件下对发泡剂YLB和发泡剂K12的泡沫粒径大小进行了测量,从微观上分析了在不同的影响因素下,泡沫的稳定性能。最后将不同类型发泡剂的排液量随时间的变化进行数学拟合,得出排液量随时间的变化关系,并将发泡剂YLB的上下层泡沫中液体含量和粒径大小随时间的变化利用K Feitosa提出的模型进行了拟合,得到上层泡沫的Deff随时间在0.96～0.93×10-6cm2/s之间变化,下层泡沫的Deff随时间在0.81～0.93×10-6cm2/s之间变化,上下层泡沫的Deff随时间变化不大,基本上是常数。证明了将泡沫的排液与泡沫粒径大小进行拟合效果较好。同时根据Lemlich理论,给出了气体扩散系数的计算方法,并分别计算了发泡剂YLB和发泡剂K12的气体扩散系数,得出JYLBJK12。也证明了,复配的发泡剂YLB较单一发泡剂K12稳定。
[Abstract]:As a main type of underbalanced drilling fluid, foam drilling fluid has many advantages, such as fast drilling speed, small formation damage, strong suspension energy, effective protection of drilling tools and drill bits, etc. The most important thing to evaluate foam drilling fluid is foaming performance and foaming stability. At present, many scholars have studied the stability of foam, but generally it is the mathematical equation analysis of a single liquid drain or a single gas diffusion, less systematic analysis of both, in order to solve this problem, In this paper, the factors affecting the stability of water-based foam and its performance evaluation are analyzed in macro and micro aspects, and the mathematical equations of foam efflux and gas diffusion coefficient are also analyzed. The main work of this paper is as follows: firstly, the foaming performance and foaming stability of eight kinds of foaming agents are evaluated. The foaming agent YLB, with a foaming height of 780mL and a half-life of 605s was selected and microscopically compared with the foaming agent YLB and foaming agent K12 by means of styroscope and Nano Measure 1.2 software. The results show that the particle size distribution of foaming agent K12 is 56.49 ~ 540.35 渭 m, the average particle size is 246.94 渭 m, and the particle size distribution of foaming agent YLB is 29.38 ~ 260.72 渭 m and 86.29 渭 m respectively. The microcosmic analysis shows that the stability of foaming agent YLB is good. Secondly, the stability of foaming agent YLB foam was investigated in laboratory under different influence factors, such as concentration, temperature, base viscosity, inorganic salt content and pH value. At the same time, the particle size of foaming agent YLB and foaming agent K12 was measured with Scion Image software at different concentration, temperature, time and PH value. The stability of foaming agent was analyzed microscopically under different influence factors. At last, the relationship between the amount of efflux and time is obtained by the mathematical fitting of the quantity of efflux of different types of foaming agent with time. The change of liquid content and particle size with time in the upper and lower layer foam of foaming agent YLB was fitted by using the model proposed by K Feitosa. The results showed that the Deff of upper foams varied with time from 0.96 to 0.93 脳 10-6cm2/s. The Deff of the lower foams varies from 0.81 to 0.93 脳 10-6cm2/s, while the Deff of the upper and lower foams varies little with time and is basically a constant. It is proved that it is better to fit the efflux of foam with the size of foam. At the same time, according to Lemlich theory, the calculation method of gas diffusion coefficient is given, and the gas diffusion coefficient of foaming agent YLB and foaming agent K12 are calculated respectively, and the JYLBJK12. is obtained. It is also proved that the compound foaming agent YLB is more stable than the single blowing agent K 12.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE254

【相似文献】