南翼山油田水蒸发结晶过程中硼酸、铵钾类光卤石复盐的形成

The scientific researches which will be carried out in this proposal are summarized as follows: (1) Based on the phenomenon that boric acid is dispersed precipitated in the evaporation salt-forming process of Nanyishan deep oil field brine, to study the influence of various elements on the properties of metastable zones of boric acid at temperature range of -20 ～30 ℃; therefore to find the main factors which cause the dispersed precipitation of boric acid, and to provide a theoretical basis for the artificial control of ore-forming process. (2) Based on the fact that lots of ammonium salts and ammonium-containing ores are found in the oil field brine, to study the effect of ammonium ion on the properties of oil field brine systems, including to explore the formation transformations of ammonium ion or amines which were formed in an underground reducing environment and were entered in the surface oxidation environment gradually, to investigate the variations of physical and chemical properties and the acidity of the oil field brine in the evaporation salt-forming process, to analyze the internal connection between nitrogen-containing (or amine- containing) organic matter and ammonium. (3) To study the comprehensive effects of temperature, pH, amine(ammonium), K+, Ca2+,Mg2+ Na+, and Cl- on the width of H3BO3 metastable zone in the temperature-variation evaporation process, and to investigate the formation conditions and mechanisms of the ammonium-containing double salts; to research the key factors for changing the brine color and ionic valence state; thus to provide theoretical guidance for the formation of ores during the process of producing high quality minerals from oil field brine.

针对南翼山地区深部卤水蒸发成盐过程中硼以硼酸形式分散析出的问题，开展(-20 ～ 30）℃温度范围内特别是低温区各主要元素对硼酸介稳区性质影响的研究，以解析硼酸分散结晶析出而不能富集的主要因素，为人工控制硼酸盐成矿提供理论依据；结合深部卤水中存在大量铵和含铵矿物形成的事实，开展铵对深部卤水体系性质影响的研究，探讨铵(胺)自地下还原环境进入地表氧化环境后的存在形式转化机理，深部卤水物化性质变化规律，蒸发析盐过程溶液酸度变因，解析油田水体系中含氮（或胺）有机质与铵之间内在联系。通过研究油田水在变温蒸发过程中温度、pH、胺（铵）、K+、Ca2+、Mg2+、Na+、Cl-等条件对H3BO3介稳区的综合影响，含铵复盐的形成条件及成矿机理，探究深部卤水中存在的致使卤水颜色、离子价态发生变化的关键因素，为油田水开发过程中盐田生产高品位矿物提供成矿理论指导。

青海省柴达木盆地西部富钾硼锂碘深部地下卤水中钾锂硼碘锶等有用组成相对比例好，品位高，为世界罕见的多元素共存特大型矿床，其中钾、锂、硼、锶远景储量均大大超过我国已探明总储量。前期研究发现在该地下卤水与钾资源共伴生的铵、硼资源影响钾资源的成矿，同时不利于硼资源的有效利用。为此对硼在深部卤水体系中的结晶行为、铵钾光卤石和铵光卤石的结晶条件以及含氮（胺）有机质、铵对深部卤水体系的影响开展研究。.确定了南翼山油田水中硼以硼酸形式存在，在油田水蒸发浓缩过程，硼始终以硼酸为主要存在形式，与一般含硼卤水中硼酸盐存在形式有明确的不同，从而解释了油田水中硼只以硼酸一种形式析出的根本原因。NaCl、KCl、NH4Cl、CaCl2多元体系硼酸结晶动力学研究结果，说明油田水硼浓缩富集程度远低于硫酸盐型富硼卤水（大柴旦盐湖，东、西台吉乃尔盐湖卤水）根本原因不是浓缩卤水pH不断降低，而是共存组分浓度变化、盐田日晒过程环境条件变化引起卤水温度改变等因素共同作用的结果。.明确油田水蒸发进入钾石盐阶段后期，结晶析出的含铵矿物是富铵光卤石固溶体，固溶体的组成与析出时的母液组成（尤其是NH4/K比）密切相关。.油田水中分析检测出188种有机质，主要包括苯，甲苯，苯乙烯，C2-C5烷基苯，苯乙醛；直链烷烃/烯烃（A），碳水化合物（Car），酚类（Ph），多聚苯环化合物（PAHs），其他苯类化合物(Ar)，氮类化合物（N），硫类化合物（S）等。随着盐田日晒工艺的推进， DOC浓度升高了4倍；日晒过程脂肪族、羧酸类化合物和碳水化合物发生光化学分解，含量逐渐减少，有少量二噁英类毒性比较大的有机污染物产生。.多组分体系中硼酸结晶动力学（介稳区）、简单体系固溶体-水溶液相平衡和热力学模型，对于存在固溶体形成的卤水加工过程具有重要的指导意义，为深部卤水开发过程中盐田生产高品位矿物提供成矿理论指导。