CN2448906Y

CN2448906Y - PDC drill bit adaptable to hard formation

Info

Publication number: CN2448906Y
Application number: CN 00251498
Authority: CN
Inventors: 孙明光
Original assignee: DRILLING TECHNOLOGY INST SHENGLI PETROLEUM ADMINISTRATION
Current assignee: DRILLING TECHNOLOGY INST SHENGLI PETROLEUM ADMINISTRATION
Priority date: 2000-09-14
Filing date: 2000-09-14
Publication date: 2001-09-19
Anticipated expiration: 2010-09-14

Abstract

The utility model belongs to the improvement of the structure of a PDC drill bit used for drilling wells of petroleum and geology. A PDC drill bit which is suitable for hard strata is mainly composed of PDC composite sheets (1), diamond teeth (2), a knife wing (3), a nozzle (4) and a drill bit body (5). The utility model is characterized in that the front end of the knife wing (3) is provided with a row of PDC composite sheets (1), and the back end of the knife wing (3) is provided with a row of diamond teeth (2) which are in one-to-one correspondence to the PDC composite sheets (1). The PDC composite sheets (1) are main cutting elements, and the diamond teeth (2) are auxiliary cutting elements. The utility model can efficiently drilling the heterogeneous hard strata with strong abradibility, and can improve the operating performance of PDC drill bits.

Description

A kind of PDC drill bit of suitable hard formation

The utility model belongs to the architecture advances of oil and geological drilling usefulness PDC drill bit.

Conventional PDC drill bit has in the soft of homogeneous or medium hardness stratum that rate of penetration is fast, the life-span long, the drilling depth advantages of higher, but in when firmly in hard heterogeneous body abrasive layer, creeping into, service behaviour is very poor, the PDC composite sheet is easy to generate cracked and the excessive wear phenomenon, causes drill bit to damage in advance.Its main cause is that the PDC drill bit is with the cut mode fractured rock, and when harder inhomogeneous formation creeps into, cause drill bit twisting vibration and axial vibration easily, simultaneously because the compressive strength height of hard formation, must strengthen the pressure of the drill and just can make PDC composite sheet wedging stratum effectively, cause the cracked and high temperature wear of PDC composite sheet easily.

The utility model mainly is made up of PDC composite sheet, diamond tooth, wing, nozzle and bit body, relies on PDC composite sheet and diamond tooth to form on wing and mixes cutting structure, can effectively creep into hard abrasive formation.The purpose of this utility model just provides a kind of PDC drill bit of suitable hard formation.

The utility model is achieved in that at wing [3] front end installs row's PDC composite sheet [1], arranges diamond tooth [2] in wing [3] rear end with the corresponding one by one installation one of PDC composite sheet [1]; Diamond tooth [2] is hanged down 0.5～1.5mm than the proud exposure of PDC composite sheet [1] on same wing [3] same radius, and is arranged in apart from 10～20mm place, PDC composite sheet [1] rear end; Diamond tooth [2] has comprised the artificial TSP of natural diamond and shapes such as triangle, cylinder.

Compare with conventional PDC drill bit, when the utility model creeps into, have all properties characteristics of conventional PDC drill bit in general stratum.When hard formation creeps into; the utility model is still based on the cutting of PDC composite sheet, but the diamond tooth of its back has been born part the pressure of the drill, has reduced the Oscillation Amplitude of drill bit; reduced the PDC composite sheet because the suffered temporary impact load of vibration has been protected the PDC composite sheet.When in abrasive layer, creeping into, the exposure gradually of the diamond tooth of wing rear end, its good heat stability makes it at high temperature still keep higher abrasion resistance and shape, rock had the effect of plough plane, mark groove at rock surface, increase the degree of freedom of rock surface, made the relatively easy fractured rock of PDC composite sheet; Diamond tooth has been born part the pressure of the drill simultaneously, has reduced the high temperature wear that the PDC composite sheet produces greatly owing to the pressure of the drill, thereby has prolonged the application life of drill bit.Therefore the utility model in hard when creeping into to the hard heterogeneous body abrasive layer, have advantages such as rate of penetration height, the life-span is long, drilling depth is Duoed than conventional PDC drill bit, can save a large amount of drilling costs, have tangible economic benefit.

Figure of description: Fig. 1. a kind of diamond bit schematic diagram description of drawings of suitable hard formation:

1.PDC composite sheet 2. diamond tooth 3. wings 4. nozzles 5. bit bodys

Now the utility model will be further described in conjunction with Figure of description:

The utility model is the composition mixing cutting structure of assisting based on PDC composite sheet [1], with diamond tooth [2], they are undertaken arranged evenly by one-to-one relationship on wing, diamond tooth [2] is than the low 0.5～1.5mm of proud exposure of PDC composite sheet [1], diamond tooth [2] distance P DC composite sheet [1] rear end 10～20mm, diamond tooth [2] is the artificial TSP of natural diamond or shapes such as triangle, cylinder.In drilling process, at first the utility model and other downhole tool are coupled together, at the bottom of the lower going-into-well, turn on pump is by downhole tool inner chamber, bit body [5] inner chamber and nozzle [4] circulating fluid then, start slewing downhole tool is rotated, and add the pressure of the drill and make its rotation fractured rock.When in general stratum, creeping into, the utlity model has the performance characteristics of conventional PDC drill bit.When hard abrasive formation creeps into, the utility model still cuts based on PDC composite sheet [1], but diamond tooth [2] has been born part the pressure of the drill, the cutting output of restriction revolution, and along with the wearing and tearing of PDC composite sheet [1], diamond tooth [2] produces the effect of plough plane to rock, marks groove on the hard formation surface, make and improved rate of penetration by the relatively easy fractured rock of PDC composite sheet [1].Simultaneously, diamond tooth [2] structure can reduce the moment excessive load that PDC composite sheet [1] is born greatly in axial, horizontal and twisting vibration, reduced the impact failure or the high temperature wear of PDC composite sheet [1], thereby prolonged the application life of drill bit.When hard abrasive formation crept into, the utility model had better economic benefit than conventional PDC drill bit.

Claims

1. the PDC drill bit of a suitable hard formation, mainly form by PDC composite sheet [1], diamond tooth [2], wing [3], nozzle [a 4] mouthful bit body [5], it is characterized in that one row's PDC composite sheet [1] being installed, arrange diamond tooth [2] with the corresponding one by one installation one of PDC composite sheet [1] in wing [3] rear end at wing [3] front end.

2. the PDC drill bit of a kind of suitable hard formation according to claim 1, it is characterized in that on same wing [3] same radius diamond tooth [2] the low 0.5～1.5mm of proud exposure, and be arranged in apart from 10～20mm place, PDC composite sheet [1] rear end than PDC composite sheet [1].

3. the PDC drill bit of a kind of suitable hard formation according to claim 1 is characterized in that diamond tooth [2] has comprised the artificial TSP of natural diamond and shapes such as triangle, cylinder.