Polar permafrost cooling drilling apparatus and method

Abstract

The present application relates to a kind of polar permafrost cooling drilling device, i.e.method, to the problem of polar environment due to drill bit friction heat generation, temperature change in well causes wellbore instability deformation, rock sample thermal metamorphism etc., provide a kind of cooling drilling device and method.The present application is to maintain the function of low temperature foam drilling fluid circulation in low temperature environment in well, the drilling device provided has air sandwich and hole slot structure, realize the circulation of low temperature foam drilling fluid in the inside of drilling sampler, play the cooling effect, and avoid contact wellbore.This device can maintain wellbore stability, protect rock sample in polar permafrost environment compared with conventional drilling device.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of polar permafrost drilling, in particular to a polar permafrost cooling drilling device and method. BACKGROUND

[0002] In the process of polar scientific exploration and other low-temperature environment geological research in China, geological condition investigation and drilling construction are important contents of research work, and have important significance for the study of geological evolution in polar and other harsh natural environments, natural resource development and environmental protection.

[0003] In the process of polar permafrost drilling, the freezing and thawing phenomenon has a great influence on drilling. When drilling in permafrost areas, heat is generated by friction in the well, causing the permafrost to thaw, the soil particles to lose cohesion, and the well wall to lose stability; when the drill bit cuts the rock, heat is generated by friction, causing the sample to melt, and the hydrate to dissolve, affecting the properties of the sample. This is a different disadvantage faced by permafrost drilling and conventional stratum drilling.

[0004] In the process of polar permafrost drilling, the drilling fluid used needs to consider the low-temperature environment. The drilling fluid needs to play the role of cooling the drill bit in addition to lubricating the drill bit, and also needs good carrying capacity of the cuttings; the discharge of the cuttings needs to consider the influence on the stability of the well wall, and as far as possible to avoid the scouring of the well wall and reduce the interference to the temperature field of the well wall.

[0005] Therefore, in the process of polar permafrost drilling, it is necessary to develop a method and related device that can ensure the stability of the well wall and the sample, effectively discharge the cuttings and protect the drill bit, and realize safe and efficient drilling. SUMMARY

[0006] The purpose of the present application is to solve the problem of temperature rise in the well due to heat generated by friction during drilling in polar permafrost, well wall thawing and instability, and rock sample metamorphism, and to provide a polar permafrost drilling device and method that maintains a low-temperature environment in the well through low-temperature drilling fluid circulation.

[0007] The technical scheme adopted by the present application is: a polar permafrost cooling drilling device and method, mainly comprising a drilling sampler, a drilling power device and a low-temperature foam drilling fluid circulation system; the drilling sampler comprises a drill bit, a drill rod, a liquid delivery device, a ball rubber sealing ring and a liquid delivery pipe connector. The drill bit and the drill rod belong to a coring drill, the drill rod is composed of three layers of casings, and the inner layer and the middle layer of casings are made of heat insulation materials. Two layers of interlayers are formed between the three layers of casings, the drilling fluid in the circulation system is transported in the two layers of interlayers, and the drill bit is arranged at the tooth root to be connected to the liquid delivery holes of the inner and outer interlayers, respectively. The liquid delivery device is connected to the drill rod and has an annular groove and a channel, and the channel is connected to the inner and outer interlayers and the annular groove, respectively. The liquid delivery device has a clamping groove, the liquid delivery pipe connector and the liquid delivery device are connected through the ball rubber sealing ring, the liquid delivery device, the drill rod and the drill bit are connected through pipe threads to form an integrated body rotating simultaneously, and the liquid delivery pipe connector does not rotate with the integrated body; the drilling power unit comprises a hydraulic drilling machine chuck and a locomotive group, the hydraulic drilling machine chuck is connected to the liquid delivery device clamping groove, and provides rotating power and propelling force, and the locomotive group is loaded with power equipment; the low-temperature foam drilling fluid circulation system comprises a liquid inlet tank, a foaming device, a cooling unit, a wellhead sealing device, a defoaming device, a mud centrifugal tank, a mud centrifugal pump, a liquid delivery pipe and a water pump, the liquid delivery pipe is connected to each device to form a low-temperature foam drilling fluid transport circuit, and a plurality of water pumps are connected between each two devices to ensure the operation of the transport circuit.

[0008] The present application has the following design features:

[0009] 1. The drill rod of the drilling sampler has interlayers, the drill bit has liquid delivery holes, the drilling fluid is transported in and out of the two interlayers in the drill rod, the drilling fluid is transported to the liquid delivery holes distributed at the tooth root of the drill bit, and the drilling fluid carrying the cuttings is extracted and recovered by the water pump on the ground through the drill rod interlayers.

[0010] 2. The inner and middle layer casings of the drill rod of the drilling sampler are made of heat insulation materials, two layers of interlayers are formed between the three layers of casings, the outer interlayer enters the low-temperature drilling fluid, the outer wall of the drill rod is cooled, the well wall is prevented from being destabilized by heat, the low-temperature drilling fluid also cools the drill bit, heat generated by friction is prevented from being conducted to the rock sample, the rock core is prevented from being metamorphosed by heat, the inner interlayer recovers the drilling fluid carrying the cuttings, the drilling fluid circulates in the drilling sampler without contacting the well wall, the drilling fluid is prevented from scouring the well wall, and the effect of maintaining the stability of the well wall is achieved.

[0011] 3. The present application uses low-temperature foam drilling fluid, the low-temperature property of the drilling fluid is used to cool the drilling sampler, and the foam has strong ability to carry rock cuttings, avoiding the plugging of the drilling sampler by mud.

[0012] 4. The present application sets up the low-temperature foam drilling fluid circulation system on the ground, the used drilling fluid can be recovered from the well, cooled and foamed again, and the drilling fluid is recycled. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 A schematic diagram of the system of the present application.

[0014] Figure 2 A cross-sectional view of the drilling sampler.

[0015] Figure 3 A perspective view of the drilling head. Figure 2 A front view of the cross-section I.

[0016] Figure 4 A perspective view of the drilling head.

[0017] Figures 1-4 I: 1 is a liquid inlet tank, 2 is a foaming device, 3 is a cooling unit, 4 is a liquid delivery pipe, 5 is a hydraulic drilling chuck, 6 is a locomotive unit, 7 is a drilling sampler, 8 is a wellhead sealing device, 9 is a defoaming device, 10 is a water pump, 11 is a mud centrifugal tank, 12 is a mud centrifugal pump, 7-1 is a liquid delivery pipe connector, 7-2 is a liquid delivery device, 7-3 is an outer sleeve, 7-4 is a middle sleeve, 7-5 is an inner sleeve, 7-6 is a liquid delivery hole, 7-7 is a rubber ball sealing ring, 7-8 is an annular groove, 7-9 is a hole, 7-10 is a drill rod, 7-11 is an outer interlayer, 7-12 is an inner interlayer, 7-13 is a drilling head, and 7-14 is a connecting pin. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be further specifically described below with reference to the accompanying drawings.

[0019] Referring to Figures 1-4 A polar permafrost cooling drilling device and method, mainly comprising a drilling sampler (7), a drilling power unit, and a low-temperature foam drilling liquid circulation system. The drilling sampler (7) is a drilling part; the drilling power unit comprises a hydraulic drilling chuck (5) and a locomotive unit (6), which provide drilling power and carrying equipment. The low-temperature foam drilling liquid circulation system comprises a liquid inlet tank (1), a foaming device (2), a cooling unit (3), a liquid delivery pipe (4), a wellhead sealing device (8), a defoaming device (9), a water pump (10), a mud centrifugal tank (11), and a mud centrifugal pump (12).

[0020] The drilling process of the drilling device is as follows:

[0021] In the liquid tank (1) to join the drilling fluid, drilling fluid in the liquid tank (1) by the water pump to the cooling unit (3) cooling, the cooling of the drilling fluid by the water pump to the foamer (2) to generate low temperature foam drilling fluid, low temperature foam drilling fluid by the water pump to the drilling sampler (7), auxiliary drilling process, the foam drilling fluid carrying cuttings by the water pump to the defoamer (9) to eliminate foam, again by the water pump into the mud centrifugal tank (11), by the mud centrifugal pump (12) to separate the drilling fluid and cuttings in the mud centrifugal tank, the drilling fluid in the mud centrifugal tank (11) by the water pump to the cooling unit (3) cooling, so the process of circulating use of drilling fluid, closed liquid tank only need to be timely supplemented by a small amount of drilling fluid liquid tank can ensure the normal operation of the low temperature foam drilling fluid circulation system.

Claims

1. A polar permafrost cooling drilling device, comprising a drilling sampler (7), a drilling power unit, and a low-temperature foam drilling fluid circulation system; the drilling sampler (7) comprises a fluid delivery pipe connector (7-1), a fluid delivery device (7-2), a ball bearing rubber sealing ring (7-7), a drill rod (7-10), and a drill bit (7-13); the drilling power unit comprises a hydraulic drilling rig chuck (5) and a locomotive unit (6); the low-temperature foam drilling fluid circulation system comprises an inlet tank (1), a foamer (2), a cooling unit (3), a fluid delivery pipe (4), a wellhead sealing device (8), a defoamer (9), a water pump (10), a mud centrifuge (11), and a mud centrifuge pump (12); characterized in that: a. The infusion set (7-2) is connected to the top of the drill rod (7-10), and the drill bit (7-13) is connected to the bottom of the drill rod (7-10). The connection is made using a pipe thread. The infusion tube connector (7-1) is connected to the infusion set (7-2). The ball bearing rubber sealing ring (7-7) is used to fix the position and seal the connection. The hydraulic drilling rig chuck (5) drives the infusion set (7-2), the drill rod (7-10), and the drill bit (7-13) to rotate, while the infusion tube connector (7-1) does not rotate with the infusion set (7-2). b. The hydraulic drilling rig chuck (5) is installed on the locomotive (6), and the hydraulic drilling rig chuck (5) is locked in the slot of the infusion device (7-2), driving the rotation and advancing the drilling sampler (7); c. Connect the inlet tank (1), foamer (2), cooling unit (3), drilling sampler (7), defoamer (9), and mud centrifuge (11) through the inlet pipe (4). Connect a water pump between each pair of devices to ensure the circulation of low-temperature foam drilling fluid. d. The drill rod (7-10) is a core drilling rod, which consists of three layers of casing. The three layers of casing are fixed by a connecting pin (7-14). The outer casing (7-3) has pipe threads at both ends, and the middle casing (7-4) and the inner casing (7-5) are made of heat insulation material. e. There are two interlayers between the three casings of the drill pipe (7-10). The outer interlayer (7-11) is used to input drilling fluid, and the inner interlayer (7-12) is used to recover drilling fluid. f. The drill bit (7-13) is a core drill bit. There are several fluid infusion holes (7-6) at the root of the drill bit teeth, which are respectively connected to the inner and outer interlayers of the drill rod and are arranged at intervals. There is only one fluid infusion hole at each tooth root.

2. The polar permafrost cooling drilling device according to claim 1, characterized in that, The infusion set (7-2) has an annular groove (7-8) and a channel (7-9). The channel (7-9) connects the annular groove (7-8) and the outer interlayer (7-11) and inner interlayer (7-12) of the drill rod.

3. A method for cooling drilling in polar permafrost, characterized in that, The polar permafrost cooling drilling method is based on the polar permafrost cooling drilling device described in claim 1 or 2. The polar permafrost cooling drilling device mainly includes: a liquid inlet tank (1), a foamer (2), a cooling unit (3), a liquid delivery pipe (4), a hydraulic drilling rig chuck (5), a locomotive unit (6), a drilling sampler (7), a wellhead sealing device (8), a defoamer (9), a water pump (10), a mud centrifuge box (11), and a mud centrifuge pump (12). The polar permafrost cooling drilling method includes the following steps: Step 1: Place the wellhead sealing device (8) at the wellhead to ensure that the well space is sealed. Add drilling fluid to the inlet tank (1), turn on multiple water pumps, and turn on the foamer (2) and cooling unit (3) to prepare low-temperature foam drilling fluid. Step 2: Start the drilling power unit and begin drilling and sampling; Step 3: Turn on the defoamer (9) and water pump (10) to extract mud, and turn on the mud centrifugal pump (12) to separate the drilling fluid and drill cuttings in the mud centrifuge box (11) to achieve the circulation of low-temperature foam drilling fluid.

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