What is the application of oil casing
Writer： admin Time：2021-07-07 14:23 Browse：℃
Cement is used to cement the well after the casing is run down. It is different from tubing and drill pipe and cannot be reused. It is a one-time consumable material. According to the specified wall thickness, welded pipe has two types: ordinary oil casing and thickened oil casing. Petroleum casing pipes are steel pipes used to support the walls of oil and gas wells during the drilling process and the normal operation of the entire oil well after completion. Each well uses several layers of casing according to different drilling depths and geological conditions. Different types of casing used in the process of oil exploitation: surface oil casing to protect drilling, support wellhead equipment and maintain casing can be divided into: conduit, surface casing, technical casing and oil layer casing. Therefore, casing consumption accounts for more than 75% of all oil well pipes.
The weight of the other layers of the pipe avoids being contaminated by shallow water and gas layers. Reservoir oil casing leads the oil and natural gas from the reservoir below the surface. Technical oil casing separates the pressure at different levels so that the drilling fluid can circulate normally and protect the production casing. In order to install anti-burst devices, leak-proof devices and tail pipes in the well. It is used to protect wells and stratify drilling mud. When the oil casing is produced, the outer diameter is usually 114.5 mm to 501 mm.
J55 oil casing is a necessary pipe material for drilling oil and natural gas, and it needs to have good performance in use. Different temperature control is used for oil casing in different temperature sections. The heating temperature of sub-temperature quenching is 780℃, and the holding time of quenching heating is 15min; heating needs to be produced at a certain temperature, AC1=736℃, AC3=810 for 27MnCrV steel ℃, the tempering temperature after quenching is 630℃, and the tempering heating holding time is 50min. The heating temperature during sub-temperature quenching is selected between 740-810℃. Since the sub-temperature quenching is heated in the α+γ two-phase zone, the quenching is carried out in the state of retaining part of the undissolved ferrite, and the toughness is improved while maintaining the temperature.
Petroleum casing is a steel pipe used to support the walls of oil and gas wells, during the drilling process and the normal operation of the entire oil well after completion. Each well uses several layers of casing according to different drilling depths and geological conditions. Cement is used to cement the well after the casing is run down. It is different from tubing and drill pipe and cannot be reused. It is a one-time consumable material. Therefore, casing consumption accounts for more than 70% of all oil well pipes. Casings can be divided into pipes, surface casings, technical casings and oil casings according to their usage.
Oil casing is the lifeline to maintain the operation of oil wells. Once the casing itself is damaged for some reason, the entire well may be reduced or even scrapped. Casing can be divided into different steel grades according to the strength of the steel itself. Due to different geological conditions, the downhole stress state is complex, and the combined action of tensile, compressive, bending, and torsion stresses on the pipe body. This raises the question of the quality of the casing itself. High demands. Namely J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Different well conditions and depths have different steel grades. In a corrosive environment, the casing itself is also required to have corrosion resistance. In places with complex geological conditions, the casing is also required to have anti-collapse properties and anti-microbial erosion.
The special oil pipe is mainly used for the drilling of oil and gas wells and the transportation of oil and gas. It includes oil drill pipe, oil casing, and oil pumping pipe. Oil drill pipes are mainly used to connect drill collars and drill bits and transmit drilling power. The oil casing is mainly used to support the well wall during the drilling process and after the completion of the well, for the progress of the drilling process and the normal operation of the entire oil well after the completion. The pumping pipe mainly transports the oil and gas at the bottom of the oil well to the ground.
Between the LC length and the disappearing point of the thread, there is a defect that the depth does not extend below the bottom diameter of the thread or not more than 12.5% of the specified wall thickness (whichever is greater), and the external chamfer (65°) of the pipe end must It is complete on the 360° circumference of the pipe end, and the chamfer diameter should make the thread root disappear on the chamfered surface instead of on the pipe end surface, and no edge-like edges should appear. The outer chamfer of the pipe end is 65°~70°; but no corrosion products are allowed on the thread surface. Grinding and dressing are allowed to eliminate defects, but filing methods are not allowed to eliminate pits. The inner chamfer of the pipe end should be 360° full round chamfer, the inner chamfer is 40°~50°, the steel grade of petroleum casing: H40, J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. . If there is any part that is not upside down, you must manually repair and file the chamfer.
Petroleum casing is a large-diameter pipe material to prevent the wellbore from collapsing while separating the rock formation and the wellbore, and to circulate the drilling mud to facilitate drilling and exploitation. Play the role of fixing oil and natural gas well walls or boreholes. The casing is inserted into the well hole, and the end of the casing is fixed with cement. The processing forms: short round thread, long round thread, partial trapezoidal thread, special buckle, etc. Used in oil well drilling, it is mainly used to support the well wall during the drilling process and after the completion of the well, for the progress of the drilling process and the normal operation of the entire oil well after the completion.