High Temperature And High Pressure Indoor Plugging Simulation System Research

Lost circulation refers to the complex circumstance of the drilling fluid leak into the pores,fractures and caves in the formation during the drilling process.And it may extend of drilling time,loss of drilling fluid and plugging materials,even lead to borehole collapses,sticking,blowout and other complex situations.Therefore,the research and application of lost circulation and plugging technology in drilling engineering are an important topic in the domestic and overseas.The bridging material,high filtration material,chemical crosslinking,chemical materials,cement and other inorganic crosslinking materials have been widely used in the process of plugging construction.Bridge plug method have been widely used as a traditional way which through adding granular,flaky,fibrous materials in drilling fluids to stop drilling fluid leakage.The success use of the plugging technology is basically depends on the bridging material matching with leakage layer.Because the invisible of the plugging process,it's imperative to take use of the plugging simulation device to simulate the conditions of the bottom hole and leakage situations which aiming to perfect the plugging process and enhanced its effects.The introduced apparatus can be heated to 300 ?,pressure to 8MPa.The instrument could simulate plugging effects which have been plugged by different types of plugging material.And it has following characters:(1)The migration way of the plugging fluid can be truly reflected in the direction of axial and vertical deep in the borehole,and to achieve continuous adjustable shearing rate.(2)Improving the intelligent degree of the instrument through the self-developed operating system.And it achieved the goal to evaluate the pros and cons of those plugging materials and measures.(3)The instrument can be used under the condition of high temperature,high pressure and dynamic,as well as observe the blocking state of plugging materials.(4)The leakage mediums are made of steel with the characters of resisting high pressure,high temperature,good repeatability,etc.(5)Replacing the traditional nitrogen gas pressure,advection pump pressure,or magnetic pump with the step motor driving type pressure to decrease the pressure fluctuation.(6)The designs of the new instrument are easy to be disassembled,cleaned and repaired.