An organic amine inhibitor was developed and evaluated. Experimental results showed that the organic amine inhibitor could decrease the surface tension to 50mN/m and had a little effect on the Zeta potential of clay. The inhibitor could effectively inhibit the dispersion of core and cuttings and had a lasting strong inhibition. The inhibitor had good compatibility with common drilling fluid, and it was useful to maintain drilling fluid stability under high temperature and could improve the filtration property of drilling fluid.

This study presents a chemical lost circulation agent with some distinct advantages that make it suitable for use in controlling severe leakage during drilling process. It is a granular solid with irregular shape and able to bridge or fill the cracks and other porous or faulty formations into where the drilling fluid is lost. Then this agent will undergo a chemical reaction with water, and the reaction products fill between particles and bind tightly lost circulation agent particles to each others or to the rocks at the lost circulation zone, thus effectively enhance the compressive strength of the cementing body formed by the agent and prevent lost circulation. Temperature, particle size, and additives added have been shown to have a significant influence on the consolidating rate and compressive strength of the cementing body. In addition, the cementing body has certain permeability, and the permeability can be adjusted, so this agent is proper for use to control lost circulation in reservoir.