摘要
在盐膏层使用盐水钻井液时,必然涉及到石膏在盐水中的溶解性问题。研究了钻井液中常用可溶性盐对石膏溶解性的影响。实验结果表明,在常用加量范围内,氯化钾、氯化镁和有机盐对石膏溶解性有促进作用,而氯化钙和硫酸钠因同离子效应对石膏的溶解性有抑制作用;在同等加量条件下,氯化钙比硫酸钠的抑制程度更强。硅酸钠会导致石膏向硅酸钙沉淀的转化,而且模数越大,这种转化越彻底。盐类对石膏溶解性影响主要受盐效应和同离子效应控制。为抑制盐膏层的溶解,可在饱和或欠饱和盐水钻井液中加入氯化钙或硫酸钠。
Solubility of gypsum must be concerned when salt-gypsum bed is drilled by salt water drilling fluid.Influence of soluble salt on solubility of gypsum is investigated in this paper.Lab results show that potassium chloride,sodium chloride and magnesium chloride promote solubility of gypsum in common concentration,calcium chloride and sodium sulfate decrease solubility of gypsum for common ion effect,moreover,calcium chloride decreases more seriously than sodium sulfate.Sodium silicate promotes solubility of gypsum because of the new precipitation generation of calcium silicate,which solubility product is smaller than calcium sulfate.Influence of soluble salt on solubility of gypsum depends on salt effect and common ion effect.To inhibit solution of gypsum,calcium chloride or sodium sulfate can be added in saturated salt water drilling fluid or unsaturated salt water drilling fluid.
出处
《钻井液与完井液》
CAS
北大核心
2013年第3期31-33,93,共3页
Drilling Fluid & Completion Fluid
基金
国家科技重大专项"大型油气田及煤层气开发"(2008ZX05030-005)部分研究成果
关键词
盐膏层
石膏
溶解度
盐水钻井液
抑制性
Salt-gypsum bed
Gypsum
Solubility
Salt water drilling fluid
Inhibition
