天然气井化学堵水新方法探讨

摘要

Water production from gas wells affects gas production. Though water shut-off is an effective method to cure water production on gas wells, the research and development on water shut-off technique has little progress, because of dififculty and risk of the treating operation, and it still locates at indoor research stage. The paper ifrstly analyzed the reason of high dififculty and high risk of gas well water shut-off, which is the demand of selective water shut-off treatment. Furthermore, based on the absorbing and referencing of the current research progress at home and abroad, from the view point of water shut-off principles, three novel types of water shut-off methods are formed. The ifrst principle is that the water shut-off agent itself has gas-water selection capacity after injected into reser-voirs;the second one is that the agent changes wettability of rock surface into more hydrophobic after getting into water beard gas for-mations, resulting in gas relative permeability increase and water relative permeability decrease;the third one is that the agent has some physical or chemical reactions when contacting water, such as expansion, assembling, or precipitation, to plug water lfow, but no reaction when contacting gas. Furthermore, the paper proposed an integrated water treatment method from the whole gas reservoir point of view.%气井出水影响气井生产，尽管气井堵水是治理气井出水的有效方法，然而该技术的研究因其操作难度大、风险大而进展缓慢，仍处于实验室研究阶段。文中首先分析了气井堵水难度大、风险大的原因在于选择性堵水的需求，进而在吸收、借鉴国内外已有研究成果的基础上研究形成气井化学堵水新方法，认为遵从三类选择性堵水原理可有效堵水，第一类是堵剂材料本身在注入地层后具有气水选择性；第二类是堵剂进入产水气层后使岩石表面润湿性向憎水方向改变，提高气相相渗，降低水相相渗；第三类是堵剂遇水发生物理、化学反应发生膨胀、聚集、或沉淀，起到堵水作用，遇气则无封堵作用。从全气藏的角度提出了气藏整体治水方法，该研究对气井化学堵水方法研究提供了借鉴。