Background technology
Employed drilling rod in the at present domestic and international petroleum gas drilling operation, substantially all adopt the API of American Petroleum Institute (API) standard, drilling rod comprises blank area and body portion, joint divides male thread joint and box thread joint, be one by being welded to connect between body and the joint, its structure is as shown in Figure 1: drilling rod comprises blank area B1, B2 and body A part, and joint divides male thread joint B1 and box thread joint B2, connects as one by welding C between body 1 and joint B1, the B2.Welded type drilling rod processing step is simple relatively, but the intensity of commissure has only about 80% of body, in order to increase the load-carrying ability of commissure, standard-required, must thicken the body end before the welding, increase the sectional area of solder side, to increase the overall load ability of commissure.
Along with the continuous development of drilling technology, inclined shaft, complicated drillng operation proportion such as extended reach well is increasing.As: Bohai Bay Oil, extended reach well accounts for 80%, the oil field, Tarim Basin, extended reach well accounts for 30%, and presents the trend of cumulative year after year.In addition, the sustained and rapid development of Chinese national economy is to the solid demand of the energy, and the lasting high-order operation of international oil price, makes that the oil-gas mining under the geological conditions such as sulfur-bearing, high sulfur-bearing becomes more and more.Domestic relatively typical case has the oil gas field of the Northeast, Sichuan; External have states such as Canada, Russia.Drilling tool both domestic and external manufacturer is at the oil gas drilling specific demand of sulfur-bearing area, developed specific drilling tool with sulfur resistance, but because the drilling rod standard that generally adopts in the world is a U.S. API standard at present, this standard code drilling rod comprises body and joint, and body and joint are connected as a single entity by welding.Metallurgy in the welding process merges and has produced the relatively poor weld seam of microstructure and property and the heat affected area on weld seam both sides, and then has influenced the sulfur resistance of sulfur resistant drill pipe, becomes the quality short slab of sulfur resistant drill pipe, also is at present the difficult point of sulfur resistant drill pipe research.
In addition, during traditional drilling rod is made, body and joint connect as one by friction welding, in order to improve the commissure mechanical load, make body and properties of its welded joints keep coupling, common way is: the body end is thickeied, increase the sectional area of weld, to guarantee that bearing capacity is constant under the situation that the strength of materials reduces.Therefore, existing processing process as shown in Figure 2, it comprises earlier carries out the end upsetting and the heat treatment of body respectively, and joint processing and joint screw thread processing, then joint and body is carried out friction welding, butt welded seam is heat-treated the formation product at last.Above-mentioned drill rocker end upsetting is divided into external upset (EU), interior thickening and internal-external thickening.Wherein, interior thickening can reduce the drill string hydrophthalmia, increase the pressure of the drill; External upset (EU) can reduce annular space, reduces drilling efficiency, and internal-external thickening had both reduced hydrophthalmia, reduced annular space again.
Summary of the invention
The object of the present invention is to provide a kind of superelevation to add the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it mainly solves the body of existing API standard drilling rod and joint welding place intensity is less, occur deficiency such as metallurgical imperfection easily, it eliminates weld seam to the drilling rod Effect on Performance, being the needs of sulfur resistant drill pipe, also is to improve the needs that the drilling rod quality promotes drilling efficiency.
The present invention solves the problems of the technologies described above the technical scheme that is adopted.
A kind of superelevation adds the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it is characterized in that: step is the straight welded joint of a body, b bulk heat treatmet, c joint and screw thread processing.
Described superelevation adds the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it is characterized in that: described step a further comprises, it is interior crassitude intermediate belt moulding thickening that a1 uses hydrostatic forging equipment to carry out first, second thickening passage, a2 is to carrying out undergauge through external upset (EU) changeover portion Meu and the external upset (EU) parallel-segment Leu that forms after first, second thickening passage, the thickening of a3 joint area makes the wall thickness of blank area be increased to required thickness.
Described superelevation adds the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it is characterized in that: described step a1 specifically is, heating-up temperature is 1150 ± 30 ℃, the tapering of the first thickening passage external upset (EU) conical surface is 1:15 ~ 1:13, adding thickness rate is 1.3 ~ 1.5, and the gap of drift and inboard wall of tube body is-0.5 ~ 1.0mm; The second thickening passage external upset (EU) conical surface tapering is 1:12 ~ 1:9, and adding thickness rate is 1.5 ~ 1.7; After the thickening of two passages is finished, body reinforcement wall thickness is increased to 1.95 ~ 2.55 times of body original wall thickness, the tapering of the male cone (strobilus masculinus) that forms is 1:12 ~ 1:9, external upset (EU) changeover portion Meu length is 130 ~ 160mm, the length of external upset (EU) parallel-segment Leu is 160-190mm, and it is 1.95-2.30 that external upset (EU) parallel-segment thickness increases multiple.
Described superelevation adds the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it is characterized in that: described step a2 promptly by the undergauge mould in radially extruding, make the process that external diameter and internal diameter dwindle simultaneously, wall thickness remains unchanged of pipe material external upset (EU) changeover portion Meu and external upset (EU) parallel-segment Leu; Through undergauge, the external upset (EU) changeover portion moves 130 ~ 160mm to the pipe end direction before the undergauge, simultaneously thickening changeover portion Miu and interior thickening parallel-segment Liu in the inboard wall of tube body corresponding position forms.
Described superelevation adds the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it is characterized in that: reaching later on by the 3rd thickening passage among the described step a3, each passage is mainly the joint area thickening, the tapering of joint male cone (strobilus masculinus) strengthens gradually, minimum is 1:11, be 1:8 to the maximum, adding the thickness rate value is 1.55 ~ 1.65, and heating-up temperature is 1150 ± 30 ℃.
Described superelevation adds the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod, it is characterized in that: when carrying out joint screw thread when partly thickening, if during for the female joint screw thread, the root of thickening drift is shaped as and screw thread conical surface tapering, the corresponding to cone of length; If during for the male joint screw thread, thickening drift root has increased with external screw thread conical surface tapering, length is corresponding to and drift is the conulite of one.
The beneficial effect of the inventive method is: (1) the present invention compares with traditional drilling rod processing method, has saved end upsetting, friction welding and weld seam heat treatment process.(2) eliminating weld seam to the drilling rod Effect on Performance by the inventive method product processed, is the needs of sulfur resistant drill pipe, also is to improve the needs that the drilling rod quality promotes drilling efficiency.
The specific embodiment
See also Fig. 3, the invention discloses a kind of superelevation and add the processing method that thickness rate is controlled to the straight forging welding hair style of type body drilling rod.As shown in the figure: this method step is the straight welded joint of a body, b bulk heat treatmet, c joint and screw thread processing.
The equipment that the inventive method is required: 500/1000 ton of hydrostatic forging equipment, 500 tons of horizontal direction pressure, 1000 tons of vertical direction pressure.75KW, 150KW medium-high frequency eddy-current heating electric furnace.
In the process of the present invention, body is finished by 4-6 thickening passage and a undergauge process by control moulding thickening technology.
Before the inventive method is implemented, at first need determining: according to net shape required behind the drill pipe thickening to the effective heated length of body, and wall thickness, the external diameter of the original pipe material of drilling rod, utilize the volume computing formula of conulite, hollow cylinder, calculate the length that participates in the original pipe material of distortion.
First, second thickening passage is interior crassitude intermediate belt moulding thickening.The thickening mode of the first thickening passage is an external upset (EU), and the second thickening passage is an internal-external thickening, and heating-up temperature is 1150 ± 30 ℃, and decide on body wall thickness, heating passage heat time heating time, and, burning overheated not occur is principle.In order to prevent unstability, the taper design of the first thickening passage external upset (EU) conical surface is 1:15 ~ 1:13, and adding thickness rate is 1.3 ~ 1.5, and the gap of drift and inboard wall of tube body is-0.5 ~ 1.0mm; The second thickening passage external upset (EU) conical surface tapering is 1:12 ~ 1:9, and adding thickness rate is 1.5 ~ 1.7.After the thickening of two passages is finished, body reinforcement wall thickness is increased to 1.95 ~ 2.55 times of body original wall thickness, the tapering of the male cone (strobilus masculinus) that forms is 1:12 ~ 1:9, male cone (strobilus masculinus) length M eu is 130 ~ 160mm, the length of external upset (EU) parallel-segment Leu is 160-190 mm, and it is 1.95-2.30 that external upset (EU) parallel-segment thickness increases multiple.
To carrying out undergauge through external upset (EU) changeover portion Meu and the external upset (EU) parallel-segment Leu that forms after first, second thickening passage.Promptly by the undergauge mould in radially extruding, make the process that external diameter and internal diameter dwindle simultaneously, wall thickness remains unchanged of pipe material external upset (EU) changeover portion Meu and external upset (EU) parallel-segment Leu.Through undergauge, the external upset (EU) changeover portion moves 130 ~ 160mm to the pipe end direction before the undergauge, simultaneously thickening changeover portion Miu and interior thickening parallel-segment Liu in the inboard wall of tube body corresponding position forms.
Carry out the 3rd passage, four-pass thickening (, can select four-pass or five passages, six passages thickening moulding) behind the undergauge according to the thickness requirement of different grade of steels.Each passage was mainly the joint area thickening after the 3rd passage reached, and the tapering of joint male cone (strobilus masculinus) strengthens gradually, and minimum is 1:11, is 1:8 to the maximum, and adding the thickness rate value is 1.55 ~ 1.65, and heating-up temperature is 1150 ± 30 ℃.For the body length that reduces to participate in being out of shape, reduce follow-up threaded portion labor content, improve raw material availability simultaneously, when upset end is fillet of tool joint pins, the 3rd has increased male joint screw thread position cone-shaped shape control section (see figure 5) to the honest and kind time thickening mould (drift part) of slender acanthopanax, and the tapering of this mould part conical surface remains unchanged at the tapering of the 3rd, the 4th, the 5th passage (adopting the thickening of five passages in case of necessity); When upset end was female joint, the 3rd had increased inner conical surface moulding section (see figure 6) to the honest and kind time thickening mould (drift part) of slender acanthopanax.
After the heating thickening and undergauge transfer of body end through four to six passages, form the joint and the body integral structure (its shape such as Fig. 4) of thickening changeover portion in having, become the straight welded joint drilling rod of body blank.After this carry out the processing of bulk heat treatmet and screw thread, just can finish whole process.
Embodiment
Body with Φ 127*9.19mm specification, S135 grade of steel is the implementation process that example illustrates the inventive method.Select 8 of the heating in medium frequency induction furnaces of 500/100 ton of hydraulic pressure thickening unit and 150KW for use.Earlier body is carried out three grades of preheatings before the processing, three times preheat temperature is respectively 650-720 ℃, and 900-1050 ℃, 1150-1200 ℃.
According to wall thickness (t), the thickness that needs thickening and the size shape requirement after the moulding of pipe material before the thickening, according to flow of metal constancy of volume principle, calculate the body length L that participates in distortion, according to 10mm≤L1-L≤50mm relation, determine effective heated length L1.Again according to 1.40,1.50,1.62,1.62 add thickness rate design process for upsetting parameter.After four passage thickenings finish, form by the direct forging molding joint of body drilling rod, formed joint area thickness is 50.65mm, and wherein allowance is 1.65mm.
The thickening of first passage is external upset (EU), and external upset (EU) changeover portion Meu length is chosen 100~130mm, and tapering is 1:11, and male cone (strobilus masculinus), outer parallel-segment length are controlled by thickening mould, and the gap of drift and tube wall is 0.00mm.
The second thickening passage is an internal-external thickening, external upset (EU) changeover portion Meu length is 130mm, the tapering of the external upset (EU) conical surface is 1:10, the length of male cone (strobilus masculinus), outer parallel-segment and shape are by the strict control of mould, in thickening changeover portion internal diameter maximum to reduce value be 3.0 ~ 5.0mm, interior thickening changeover portion plays height and the first passage external upset (EU), and to play height consistent.Because first passage is only carried out external upset (EU), second passage is carried out internal-external thickening, thickeies freely superposeing of changeover portion in not having, and therefore after the thickening of second passage, the surface smoothing fairing pit and projection can not appear, in the micro-reinforcement of pipe material inwall formation.
After second passage has been thickeied, carry out undergauge and shift.Promptly by the undergauge mould in radially extruding, external diameter and the internal diameter of pipe material external upset (EU) changeover portion Meu and external upset (EU) parallel-segment Leu dwindled simultaneously, wall thickness remains unchanged.Through undergauge, the outer transition conical surface by the strict control of mould moulding is reversed and transfers to inboard wall of tube body, the thickening transition conical surface in forming.The actual increase of outer parallel-segment place external diameter 6-7mm, interior parallel-segment actual inner diameter reduces 3-4mm.
After twice thickening, the wall thickness of end upsetting parallel-segment is 19.30mm.According to flow of metal constancy of volume principle and definite in advance good joint geometry size, calculate the height and effective heated length that connect the 3rd passage, four-pass, the male cone (strobilus masculinus) tapering of the 3rd thickening passage is 1:11 ~ 1:9, adding thickness rate is 1.62; The male cone (strobilus masculinus) tapering of the 4th thickening passage is 1:10 ~ 1:8, and adding thickness rate is 1.62.Three, the 4th thickening passage is only carried out external upset (EU), and heating-up temperature is 1150 ± 30 ℃.
For the pipe material length that reduces to participate in being out of shape, reduce the workload of follow-up screw thread processing, the punch structure design feature of the 3rd thickening passage is: when the thickening target was tool joint box, the drift root was cone (as Fig. 6), and the tapering that requires of the tapering of this conical surface and joint screw thread is consistent; When the thickening target was fillet of tool joint pins, the drift root had increased male joint screw thread position cone-shaped shape control section (as Fig. 5), and the tapering of this conulite is consistent with target male joint thread taper.
Three, four-pass (the 5th passage is arranged in case of necessity) external upset (EU), drift (cylindrical section) is 0.00 ± 2mm with the gap of pipe material inwall, because drift is to the restriction of the distortion of inboard wall of tube body, flow of metal can only be along radially outward flowing in portion's mould an actor's rendering of an operatic tune, and therefore the three or four thickening passage can use the superelevation that surpasses conventional way to add thickness rate (adding thickness rate greater than 1.6).
Three, after the 4th (the 5th passage is arranged in case of necessity) thickening was finished, the joint area blank of the straight forging welding hair style of control moulding body drilling rod just forged and finishes.Be characterized in: joint type is directly thickeied to forge through body and is formed, and does not have weld seam, and the material property of joint and body is consistent.
Drilling rod blank after thickening finishes need carry out bulk heat treatmet, makes the tissue of drilling rod integral material become tempered sorbite.
Carrying out the screw thread processing of joint area after the heat treatment.So far, whole process finishes.
In sum, be preferred embodiment of the present invention only, be not to be used for limiting practical range of the present invention, promptly all equivalences of doing according to the content of the present patent application claim change and modify, and all should be technology category of the present invention.