Coal Mine Deep Well Ground Drilling Drainage Well Design And Construction Key Technology

The exploitation of deep coal resources, water problem is very serious. Xieqiao coal mine, to improve drainage capacity, constructs drainage well. This paper uses the method of theoretical analysis and numerical simulation to analysis the design and the key technology of construction of the drainage wellThe design of the drainage wells, using the method of uniaxial stress, can be divided into the external pressure strength design, the tensile strength design and the internal pressure strength design. The casing has two mainly kinds of forms of external pressure collapse:one kind is technical casing and work casing lacking of stability, the casing buckling; another is the technical casing and work casing lacking of strength, The tube wall of casing yield. When the casing buckling, the critical load is calculated using the theoretical formula presented in the paper. When the casing yield, calculation uses the fourth strength theory. In the process of construction, using the lifting method sinks technology casing, using the lifting and buoyancy method sinks work casing, using the Intubation wellhead sealing method cements well. Through the method of numerical simulation to study the problem of external pressure collapse of the casing, we prove the reliability of the theoretical formula, and a method was presented to improve the stability of the casing. The casing can be regarded as a thin-wall structure to design. The achievements of this thesis can provide some reference for the design and construction of the drainage wells in the future.