Abstract: A laboratory device for simulating the cement sheath consolidation in the frozen soil strata includes the main body, the pressure system and the measuring system. The main body includes the fixing plate, the detachable plate and the base plate. The circular hole is provided in the center of the base. The central column or the heat insulating casing is mounted on the base through the circular hole. The fixing plate, the detachable plate, the base plate and the central column or the heat insulating casing form a cavity for preparing the core and the cement sheath. During use, the device is placed in a low temperature context, and then the frozen soil core with a hollow cylinder can be artificially fabricated. Further, the heat insulating casing holder is placed, and the cement is added to simulate the state of the cement sheath consolidation under the actual strata conditions.

Abstract: A drilling casing includes a casing wall and several sand control apparatuses disposed on the casing wall in a spacing. Each sand control apparatus includes a sand control net, a sealing steel sheet and a sealing rubber plug. A plurality of mutually-paralleled sand control meshes are disposed on the sand control net. The sand control mesh exactly faces the sealing steel sheet. The sand control net is connected with the sealing steel sheet through a steel pin. Further, a method of performing fast drilling and completion of a large-borehole multilateral well by the drilling casing includes forming a main borehole by drilling to a destination well depth at one time with a large-size drill bit, drilling a lateral borehole in a natural gas hydrate reservoir by using the drilling casing, and taking out the drill bit for completion. The method is applicable to various natural gas hydrate extraction manners.

Abstract: Disclosed are a device and a method of drilling a hydrate micro-borehole and performing fast completion, which belongs to the technical field of a hydrate extraction device and a hydrate extraction method. The method includes a continuous operation machine, a power control mechanism, a high pressure water jet pump, a guider, a continuous pipe, a parent pipe and a child pipe, the parent pipe is connected with the continuous operation machine, and an end of the child pipe is connected with a water jet nozzle; the working method basically includes the following: firstly, a large main borehole is formed by drilling to a destination layer at one time with a large size drill bit; secondly, a horizontal micro-borehole is drilled in a natural gas hydrate reservoir by a high pressure water jet device formed by the child and parent pipes and then the child pipe is heated to enable its skin to fall off and leave a screen; finally, the child and parent pipes are disconnected to perform well completion.

Abstract: Disclosed are a device and a method of drilling a hydrate micro-borehole and performing fast completion, which belongs to the technical field of a hydrate extraction device and a hydrate extraction method. The method includes a continuous operation machine, a power control mechanism, a high pressure water jet pump, a guider, a continuous pipe, a parent pipe and a child pipe, the parent pipe is connected with the continuous operation machine, and an end of the child pipe is connected with a water jet nozzle; the working method basically includes the following: firstly, a large main borehole is formed by drilling to a destination layer at one time with a large size drill bit; secondly, a horizontal micro-borehole is drilled in a natural gas hydrate reservoir by a high pressure water jet device formed by the child and parent pipes and then the child pipe is heated to enable its skin to fall off and leave a screen; finally, the child and parent pipes are disconnected to perform well completion.

Abstract: Disclosed is a new drilling casing, including a casing wall and several sand control apparatuses disposed on the casing wall in a spacing, wherein each sand control apparatus includes a sand control net, a sealing steel sheet and a sealing rubber plug, a plurality of mutually-paralleled sand control meshes are disposed on the sand control net, the sand control mesh exactly faces the sealing steel sheet, and the sand control net is connected with the sealing steel sheet through a steel pin. Further a method of performing fast drilling and completion of a large-borehole multilateral well by using the new drilling casing is disclosed. a main borehole is formed by drilling to a destination well depth at one time with a large size drill bit, a lateral borehole is then drilled in a natural gas hydrate reservoir by using the new drilling casing, and then, the drill bit is taken out for completion. The method is applicable to various natural gas hydrate extraction manners.

Abstract: A laboratory device for simulating the cement sheath consolidation in the frozen soil strata includes the main body, the pressure system and the measuring system. The main body includes the fixing plate, the detachable plate and the base plate. The circular hole is provided in the center of the base. The central column or the heat insulating casing is mounted on the base through the circular hole. The fixing plate, the detachable plate, the base plate and the central column or the heat insulating casing form a cavity for preparing the core and the cement sheath. During use, the device is placed in a low temperature context, and then the frozen soil core with a hollow cylinder can be artificially fabricated. Further, the heat insulating casing holder is placed, and the cement is added to simulate the state of the cement sheath consolidation under the actual strata conditions.