SU1120108A1 - Method of running casing string into a well - Google Patents

Abstract

The method of running the casing column into a drill, including building up the casing string and pumping into it of the drilling fluid with the removal of sludge through the annulus, characterized in that, in order to provide the casing of a large diameter, the air is pressurized to the casing to equal the pressure of the casing string to equal the pressure of the casing string to the casing string equal to the pressure of the casing string of equal diameter. in the annulus at the height of emptying, a after the release of flushing fluid from the tubular space into the casing continue to pump the fluid before lowering it to the bottom, and complete air bite.

Description

I1 The invention relates to mining and is intended to clean the bore of a predominantly large diameter. A known method of preparing a well bore during the descent and plugging of casing strings concludes with the drilling of the well bore through a drilling tool lowered to the slab before the descent of the column, and pumping the excess mud after the descent of the column to slaughter P. The disadvantage of this method is the impossibility of its implementation in those cases when the walls are well-unstable and give shedding of particles. The closest in technical essence and the achieved result to the invention is a method of lowering the casing string into the well, including 1191th building up the casing and pumping washing fluid into it with the removal of sludge through the annulus O. The disadvantage of the known method is that it does not. can be used when running the casing afloat when the mass of the casing exceeds the carrying capacity of the drill bit. The aim of the invention is to provide a casing with a large diameter. This goal is achieved in that, according to the method of lowering the casing string into the well, including casing string injection and pumping washing fluid into it with removal of cuttings through the annulus, air is injected into the casing to a pressure equal to the pressure of the flushing fluid in the annulus at the height of emptying, and after the flushing fluid leaves the casing space in the casing string, the fluid continues to be injected until it is lowered to the bottom, and the air is fully filled. FIG. 1 shows the position of the casing in the well, during descent and afloat {in FIG. 2 - position in the well after the build-up of the casing and installation of the lead pipe with a flushing head and air supply; on phage. 3 - position in the borehole while maintaining the air pressure in the column and injecting into it a propeller fluid; in fig. 4 - the end 8 of the washing of the well from sludge and the casing on the bottom of the well / in FIG. 5 - polyshenie downhole after flushing from the sediment asham and replacing air with flushing fluid. The method is carried out as follows. In the well 1, filled with liquid 2, the casing 3 with a check valve 4 is lowered to the sediment of louse 5 at the bottom 6. To reduce the load on the rig, the column is emptied to a depth of 7. After the casing reaches the upper limit of the sludge sediment 5, it is increased the casing section 8 and, in the upper end, install the lead pipe with a piercing head 9, the total length of the extension pipes must be equal to or greater than the height of the sludge sludge 5 at the bottom 6, the flushing head 9 with nozzles 10 and 11 are equipped with valves 12 and 13 and ma No. 14. A compressor is then connected to the pipe 10 and the valve 12 is opened. From the compressor through valve 12 and pipe 10, air 15 is pumped into the column to a pressure close to the pressure of the liquid column in the annulus equal to the emptying depth of the column. When such air pressure in the string is reached, liquid 2 leaves well 1. At the same time, the weight of the string on the rig hook does not change. After the outflow of fluid 2 from well 1 begins, the co-pressor is disconnected. A drilling pump (not shown) is connected to the nozzle to, and through the valve 12, pumping fluid 16 is pumped, which, under its own weight, is lowered into the lower part of the column 3 and flowed through the bag 17, while washing the sediment 5 and removing it from well 1 to day surface. Simultaneously with the release of the sludge sediment 5, the casing 3 is lowered. At the same time, its weight remains constant at the derrick's rig, since air 15 is held in the upper part of the casing string. After the sludge sludge 5 is completely removed from the bottom 6 and the casing 3 is lowered 6, the valve 13 is gradually opened and the air 15 is fed out of the casing 3 and, simultaneously, through the valve 12, the flushing fluid 16 is pumped into the column 3 until the air is completely 15. At this, the washing process of the bottom hole from the sludge sludge 5 ends. After that, casing column 3 is prepared for cementing.

The use of the invention allows floating large-diameter sledged columns afloat, which reduces the power consumption of lifting equipment.

FIG.

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VuiA Figure 5

Claims (1)

METHOD FOR DRAINING THE Casing COLUMN INTO A WELL, including building up the casing string and pumping flushing fluid into it with the removal of sludge through the annulus, characterized in that, in order to ensure the casing string is large-sized, the air is pumped into the casing to a pressure equal to the pressure of the flushing fluid in the annulus at the emptying height, and after the flushing fluid exits the annulus into the casing, the fluid continues to be pumped until it is lowered to the bottom and completely discharged into zduha. 1 1120108