RU1804541C - Method for control of drilling mud circulation - Google Patents

Abstract

The invention relates to the mining industry and can be used when drilling deep oil and gas wells to prevent complications in an open wellbore at the time of a circulation call and to increase the safety of workers. SUMMARY OF THE INVENTION; The method includes starting the drilling pump 1 and causing circulation through the well by moving the starting valve to the closed position. In the process of drilling, termination;.;:.;.; .. :: ..- at 2: ;; ;;;. circulation is carried out by stopping pump 1. The outlet of one of the starting valves is equipped with a starting pressure limiting unit. A circulation call is made when the starting pressure is limited by closing one of the starting valves and opening the other, the outlet of which is equipped with the indicated assembly. The pump 1 for stopping the circulation is stopped when the other starting valve is closed and the first one is open. In this case, the value of the starting pressure limitation at the time of the circulation call is selected from the calculation of preventing complications in the open, wellbore. Application of the method allows to prevent hydraulic fracturing of rocks 8 in an open wellbore and to prevent the occurrence of complications for These / reasons; & also improve the safety of performers. 3 silt, WITH

Description

The invention relates to a technology for controlling mud circulation during drilling of deep wells.

The aim of the invention is to expand the technological capabilities of the method. ;

This is achieved by the fact that in the known method, which includes starting the mud pump and calling the circulation through the well by moving the start valve to the closed position, flushing the well and stopping the circulation by stopping the pump, removing one of the starting valves, equip the start pressure limiting unit, call the compasses This is done when the starting pressure is limited by closing one starting valve and opening another starting valve, the outlet of which is equipped with a starting pressure limiting unit, and the stop is wasp to stop the circulation is effected at the starting gate valve closed, which outlet is equipped with a knot-limiting -puskovogo pressure at the time the call is selected circulation rate of preventing complications in an open wellbore.

Fig. 1 is a schematic diagram of a mud control circuit in the presence of one mud pump; Fig. 2 is the same if there are two or three mud pumps in the piping.

The diagrams show (see FIG. 1) a mud pump 1 connected to a mznifold 2 via a flow line 3, on which a safety valve 4 with a flow valve 5 is installed. On the manifold 2, a starting valve 6 with a branch 7 and a starting valve 8 with a branch are installed 9 and starting pressure limiting assembly 10. The assembly 10 is made in the form of a replaceable diaphragm installed between the starting valve 8 and the tap 9, The replaceable diaphragm is made in the form of a ring, the diameter of the hole in which is selected depending on the expected pressure at the time of the circulation call, in order to prevent complications in the open well deviation .

.Example. Let us show the application of the method when drilling wells in Western Siberia (Nobr district of the Tyumen region).

Well depth 2800 m, turbine drilling method, working pressure 170 kgf / cm2 Drilling fluid: beats. weight - 1.12-1.14 g / cm3, viscosity 25-30 s, SNS 12-26 mgf / cm. The hydraulic fracturing pressure of the open part of the barrel is 55 kgf / cm2. Drilling is carried out by a single U8-6M pump with cylinder liners with a diameter of 160 mm with a capacity of 30 l / s.

A diaphragm of such a size is installed on the starting valve 8 in the node 10 so that when pumping the drilling fluid with the pump 1 through the node 10, the pressure in the manifold 2 does not exceed 50 kgf / cm2. A ring with an inner diameter of 24 mm meets these requirements. Depending on the hydraulic resistance that occurs when pumping the drilling fluid,

a certain part of it passes through node 10 and branch 9. The amount of pumped drilling fluid through the manifold 2 (respectively, and through the well) and node 10 are inversely proportional

the resulting hydraulic resistance. E. if the pressure of 50 kgf / cm is not enough to cause circulation through the well, the entire drilling fluid will be pumped only through the unit

10 and branch 9. The internal cavity of the drill

columns and lower part of the wellbore

while they are in a pre-loaded state

under a pressure of 50 kgf / cm. As a result of such work, the mud pump harness 1- in it

water hammer does not occur. All strapping elements operate with a smooth increase in pressure to no more than 50 kgf / cm.

Mud circulation control is performed as follows.

The tap 9 of the gate valve 8 is equipped with a knot 10 for limiting the starting pressure to 50 kgf / cm2. Before starting the mud pump 1, close the starting valve 6 and open the starting valve. 8, on which

start-up pressure limiting unit 10 is installed. The mud pump 1 is started. Since unit 10 is set to 50 kgf / cm2, at the time of circulation circulation through the well, the pressure cannot rise above 50

kgf / cm After circulating through the well, the pressure in the manifold drops to 20-30 kgf / cm2, and the drilling fluid begins to circulate through the channels (they are not shown in the drawings). At this point, part of the drill

fluid will exit through unit 10 and outlet 9. After making sure that the drilling fluid is circulated through the junction normally, the gate valve 8 is closed. From this moment, the entire drilling fluid is pumped through manifold 2 and the well

Start drilling the well. At the same time, a working amount of drilling fluid is supplied to the well - 30 l / s at a pressure of 170 kgf / cm. After drilling is completed, the drill string is lifted from the bottom by 10-15 m and the mud pump is turned off after flushing the well. As soon as the pressure in the manifold 2 drops to zero, open the gate valve 6. The drilling fluid located in the drill hose, stand (not shown in the drawings) and the manifold 2 flows into the receiving tank through outlet 7. The absence of unit 10 here allows the drilling it is more likely to drain the solution, which is especially important in winter time in order to avoid freezing of communications.

The application of the proposed method for controlling mud circulation allows expanding the technological capabilities of performers due to the possibility of adjusting the starting pressure when circulating through the well is caused depending on the state of the open wellbore. This prevents complications in the well and increases labor safety.

Claims (1)

Formula for Acquisition A method of controlling mud circulation, including starting the mud pump and causing circulation through the well by moving one start valve to the closed position, flushing the well during drilling and stopping the circulation by stopping the pump, which are distinguishing. that, in order to expand technological capabilities, the discharge of one of the start-up valves is equipped with a start-up pressure limiting unit, a circulation call is made when the starting pressure is limited by closing one start-up valve and opening another start-up valve, the tap of which is equipped with a start-pressure limiting unit, and the pump is stopped to stop circulation t when closed a start-up valve, the tap of which is equipped with a Start-up pressure limiting unit and another start-up gate open, wherein the amount of start-up pressure restriction at the time of the circulation call is selected from the calculation of preventing complications in an open wellbore,