基于Plackett-Burman设计的气井采出水储罐安全研究

Safety research on gas well produced water storage tank based on Plackett-Burman design

关键词:  气井采出水  储罐  杂质  检测分析  气-液相平衡  Plackett-Burman设计

Key words:  gas well produced water  storage tank  impurities  determination and analysis  vapor-liquid phase equilibrium  Plackett-Burman design

摘要:

针对天然气气井采出水储罐可能存在易燃易爆安全风险的实际生产问题,首先利用X射线衍射仪、离子色谱仪、气质联用仪对气井采出水中的固体杂质、无机杂质和有机杂质进行了检测分析,并利用Plackett-Burman设计通过室内实验研究了不同杂质含量下气井采出水体系的气-液相平衡变化规律。结果 表明:气井采出水中的杂质主要包括Fe₃O₄等固体杂质、K⁺等无机杂质以及甲酸等有机杂质几大类；与纯甲醇-水体系相比,杂质会对气井采出水的气-液相平衡产生不同程度的影响且总体上表现出一定的正偏差；在这些杂质中,FeS、MgCO₃、K⁺、Ca²⁺、F-、甲酸、正癸烷、正庚烷、1,2,4-三甲基苯和乙基环己烷等对甲醇气相摩尔分数均存在显著影响,其中乙基环己烷影响最大,Ca²⁺次之,FeS最小。研究结果可为气井采出水储罐安全运行提供科学、可靠的理论依据和数据来源,同时对同类型设备也具有一定的借鉴作用。

Abstract:

Aiming at the severe problems of possibilities for flammable and explosive risks during the actual production procedure, the X-ray diffractometer, ion chromatography and GC/MS were used to detect and analyze solid impurities, inorganic impurities and organic impurities in the gas well produced water initially. Then the changing law of vapor-liquid phase equilibrium of the gas well produced water system with diverse impurities under different contents was explored by laboratory experiments using the Plackett-Burman design. The results showed that the impurities in the gas well produced water mainly include solid impurities such as Fe₃O₄, inorganic impurities such as K⁺, and organic impurities such as formic acid. The impurities could affect the gas-liquid phase equilibrium of gas well produced water to different degrees. Compared with the pure methanol-water system, the impact shows a certain positive deviation overall. Moreover, FeS, MgCO₃, K⁺, Ca²⁺, F-, formic acid, n-decane, n-heptane, 1,2, 4-trimethylbenzene and ethylcyclohexane among these impurities have significant influences on the molar fraction of methanol in vapor phase, among which ethylcyclohexane has the greatest effect followed by Ca²⁺, and FeS is the smallest. The research results could provide a scientific and reliable theoretical basis and data source for the safe operation of gas well produced water storage tanks, and a reference to the same types of equipment.