Direct circulation cementing unit and cementing method that well for storage of high pressure gas is novel
Technical field
The present invention relates to high-pressure gas storage well and carry out a kind of direct circulation cementing unit and cementing method in the empty cementing practice process of gas storage well steel pipe pit shaft outer shroud.
Background technology
Store the well for storage of high pressure gas plurality of advantages such as other caissons are safe owing to having relatively, and risk is low of compressed natural gas, be widely used in places such as CNG gas station, city gas peak regulation station.Gas storage well has developed swift and violent since 2002 include the national standard standard in the whole nation; Because oil price promotion in recent years; Natural gas makes its purposes very extensive as alternative energy source of oil not only environmental protection but also economy, replaced gas bomb, the gasholder status at gas station, peak regulation station at present basically.
As influencing the gas storage well crucial worker of the security of operation preface " well cementation " of constructing in the future in the gas storage well building course, the cementing method that in present work progress, adopts, all in various degree exist the deficiency that some are difficult to overcome.
The kind and the deficiency of existing gas storage well cementing method:
1. utilize soft plain boiled water band to realize well cementation from the outer annular space of sleeve pipe, there is following shortcoming in this kind well cementation:
1. carelessness and the error owing to the operator causes the damage to the plain boiled water band easily in the setting of casing process.
2. this kind cementing method is to the having relatively high expectations of stratum, generally be applicable to earth formation more stable and can guarantee cementing quality preferably during for the stratum of light weight mud drilling well.Otherwise instead then.But it is low that the advantage of this kind well cementation is a difficulty of construction, and low and quality pit shaft of cost is guaranteed easily.
3. plain boiled water band self intensity is low, and difficulty satisfies the requirement of gas storage well to well depth.
2. utilize drilling rod to realize the direct circulation well cementation; This mode should be the developing direction of present gas storage well cementing method; But because will be in bottom (head) perforate and realization shutoff, difficulty of design and construction is all very big, and all there is deficiency in therefore at present existing several kinds of direct circulations well cementation mode:
1. residual cement cleans the airtight quality of influence to bottom (head) than difficulty in the well of well cementation back.
2. generally after well cementation, be mostly to realize shutoff to bottom (head) with plug, owing to the degree of depth reason of well, on detain difficulty and cause cross threading more easily, and the influence sealing is prone to leak.
3. to the operation require high.Because operator's carelessness and error will cause gas storage well and gas storage well well location to scrap easily because of pressure testing is defective enormous economic loss, construction risk is high.
Summary of the invention
The object of the invention just provides the novel direct circulation cementing unit of a kind of well for storage of high pressure gas.This device is the important innovation to several kinds of present cementing units; Except realizing that cementing quality of the present invention well, sealing is high, can secondary seal; Well cementation back cement paste is pollution-free etc. to gas storage well steel pipe inwall, greatly reduces the risk that the gas storage well construction is scrapped.
Another object of the present invention provides the novel direct circulation cementing method of a kind of well for storage of high pressure gas.
The direct circulation cementing unit that well for storage of high pressure gas is novel is characterized in that: be made up of bottom (head) 1, stainless steel plug 2, plug depression bar 3, the second road plug 4, casing coupling 5, sealing ring 6, bolt 7; The bottom of bottom (head) 1 is porose 11, and the bottom cylinder of stainless steel plug 2 is identical with the diameter in hole 11 and put in the hole 11, and the cylinder outer ring, bottom of stainless steel plug 2 is equipped with sealing ring 6; The middle part of stainless steel plug 2 is tapered; The upper end of stainless steel plug 2 is connected with bolt 7 with the bottom of plug depression bar 3, and the inner ring of plug depression bar 3 is a drum, and sealing ring 10 is installed in the epimere outer ring of plug depression bar 3; There is screw thread 31 outer ring, stage casing of plug depression bar 3, and there is screw thread 31 in the stage casing of bottom (head) 1 inwall; The second road plug 4 be shaped as the cylinder hat, the second road plug 4 is socketed in that the upper end of plug depression bar 3 is outside, the top of the second road plug 4 is fixedly connected nut 12, the slip joint casing box cupling 5 in the epimere outer ring of bottom (head) 1.
The direct circulation cementing unit that described well for storage of high pressure gas is novel is characterized in that: the plug of specification when the second road plug 4 is 3-5.
The direct circulation cementing unit that described well for storage of high pressure gas is novel is characterized in that: well cementation connector 8 is sleeve-shaped, and the upper end of well cementation connector 8 is the horn mouth shape, and screw thread 81 is arranged on the horn mouth, and the well cementation connector is outside equipped with sealing ring 10 in 8 lower ends.
The direct circulation cementing method that well for storage of high pressure gas is novel is characterized in that: carry out following steps in order
Step 1, brill vertical shaft; The dark 20-300 rice of vertical shaft;
Step 2, in floor-mounted, vertically after the assembling, the plug depression bar 3 of screwing compresses stainless steel plug 2 in the hole 11 of bottom (head) 1 with bottom (head) 1, stainless steel plug 2, plug depression bar 3, box cupling 5; The second road plug 4 is not installed before the well cementation.
Step 3, carry out the hydrostatic test on ground: connect pipeline on ground and carry out the water pressure testing, the assembly of the bottom (head) 1 that assembles, stainless steel plug 2, plug depression bar 3 is carried out the hydrostatic test, to hydraulic pressure be 33Mpa-42Mpa; Voltage stabilizing 10-50 minute; It is qualified detecting leakproof, if hydraulic pressure is defective, explain that bottom (head) 1 and stainless steel plug 2 are off quality or install defective; Change bottom (head) 1 and stainless steel plug 2, carry out the hydrostatic test after reinstalling until qualified;
Step 4, cementing unit is installed in well, with the assembly of the bottom (head) that assembles 1, stainless steel plug 2, plug depression bar 3 along the shaft bottom of falling under the well head; Carry out casing job then: confirm the number of casing coupling 5 and steel pipe casing coupling 5 to be enclosed within on the bottom (head) 1 according to the degree of depth of well, with steel pipe socket on casing coupling 5, mounting sleeve box cupling 5 and steel pipe step by step in order;
Step 5, make a strength test, mainly detect the intensity of sleeve pipe, water pipe is poured water in well from ground, and progressively being forced into hydraulic pressure is 33Mpa-42Mpa; Voltage stabilizing 3-8 hour, it was qualified that hydraulic pressure does not have pressure drop; If defective, then take out sleeve pipe, casing replacing more is in case gas storage well and sleeve pipe scrap, until qualified;
Step 6, carry out the direct circulation well cementing operation, carry out according to the following steps:
A, the connector 8 of will cementing the well are enclosed within on the plug depression bar 3,
When B, well cementation, rotary drill rod is connected drilling rod with well cementation connector 8; Joint face is at screw thread 81 places, and drilling rod down arrives shaft bottom with drilling rod by root with after well cementation connector 8 is connected; It is fastening that drilling rod is connected, and well cementation connector 8 is a sleeve-shaped, and the upper end of well cementation connector 8 is screw thread 81 connector shapes; During well cementation, with Type B pincers every drilling rod is tightened in the going down process, get into the top such as the shown position of plug depression bars 3, be outside equipped with sealing ring 10 in the well cementation connector 8 and be used for the shutoff cement paste and prevent in the cement paste entering sleeve pipe through well cementation connector 8 front ends guiding 82;
C, counter-rotating drilling rod withdraw from stainless steel plug 2 in the bottom outlet 11 of bottom (head) 1; (moving back button length is controlled at about 30mm--60mm; Do not thread off to guarantee plug depression bar 3 and bottom (head) 1), connecting the well cementation pump will grout in, along the diagram direction of arrow; Grout in from the top down and be followed successively by: the outside 23 of the hole 11--bottom (head) 1 of inner chamber 22--bottom (head) 1 bottom of the hole 9--bottom (head) 1 on the inner chamber 31--plug depression bar 3 of the inner chamber 83--plug depression bar 3 of well cementation special joint 8; Until injecting gas storage steel pipe outer annular space, fill whole outer annular space, thereby realize the direct circulation well cementation;
After D, well cementation are accomplished, inject clear water and replace out cement paste in the drilling rod, clean drilling rod and bottom (head) bottom outlet 11; The clear water amount is greater than the drilling rod internal volume; After shutting surface water mud pipeline valve, prevent that cement paste from returning in the drilling rod, is rotated in the forward drilling rod; Tighten plug depression bar 3 to compress stainless steel plug 2, realize sealing for the first time; On carry drilling rod and take out drilling rod, take out well cementation connector 8;
Step 7, sealing for the second time: the plug when the second road plug 4 is 3-5 for specification; Become the conical surface seal plug; Its sealing principle is with sealing for the first time, and its structure is that buckle in the cover pipe range garden when screw thread partly is 3-5; Sealing is high, and the second road plug, 4 front ends are provided with guide end 13 and are not easy thread alternating when guaranteeing to detain; Through drilling rod the second road plug 4 is sent in the well, be rotated in the forward drilling rod, tighten screw thread, moment of torsion meets API moment of torsion standard-required; Because the effect of sealing is for the first time arranged, and cement paste there should be no return in the gas storage steel pipe, therefore guaranteed the cleaning and the sealing effectiveness of screw thread part.
The direct circulation cementing method that well for storage of high pressure gas is novel the invention has the beneficial effects as follows with original compared with techniques:
1. be different from and lean on traditional direct circulation cementing unit to lean on the back pressure valve sealing, the present invention guarantees that drilling mud does not return in the sleeve pipe in the setting of casing process, has greatly improved gas storage well sealing, reliability.
2. be different from traditional direct circulation well cementation and need on the shaft bottom, occurring thread alternating easily, the great risk that causes sleeve pipe and well location to scrap by button after the well cementation.The present invention seals for the first time because when button was moved back in well cementation, plug depression bar 3 was not threaded off with bottom (head) 1, and easy thread alternating causes the useless great risk of gas storage steel pipe crossfire when therefore having avoided shaft bottom, traditional direct circulation well cementation back make-up.
3. the present invention is because its special construction, prevented that cement paste from getting back in the steel pipe, therefore guaranteed the cleaning and the sealing effectiveness of screw thread part.Overcome traditional direct circulation masty difficult problem of cementing the well.
4. the present invention has realized double containment, makes sealing more reliable and secure, and conical surface seal is adopted in the sealing of first road, and the middle part of stainless steel plug 2 is tapered; Sealing for the second time: the plug when the second road plug 4 is 3-5 for specification; Structure is: buckle in the cover pipe range garden when screw thread partly is 3-5; Sealing is high, and the second road plug, 4 front ends are provided with guide end 13 and are not easy thread alternating when guaranteeing to detain, the second road plug 4 be shaped as the cylinder hat; The second road plug 4 is socketed in the outside, upper end of plug depression bar 3, and the nut 12 of fixed connection is arranged at the top of the second road plug 4; Through drilling rod the second road plug 4 is sent into and to be rotated in the forward drilling rod in the well and to tighten screw thread, moment of torsion meets API moment of torsion standard-required.The first road seal form is less demanding to the condition of sealing surface, and device has guaranteed the clean of the second road seals at.Because the effect of sealing is for the first time arranged, and cement paste there should be no return in the gas storage steel pipe, therefore guaranteed the cleaning and the sealing effectiveness of screw thread part.
Description of drawings
Accompanying drawing 1 is the axial sectional view of the novel direct circulation cementing unit of well for storage of high pressure gas of the present invention.
Accompanying drawing 2 is the novel direct circulation of well for storage of high pressure gas of the present invention well cementation cementing methods when in this cementing unit, using, the axial sectional view of this cementing unit.
The specific embodiment elaborates to the present invention below in conjunction with accompanying drawing:
See Fig. 1, the direct circulation cementing unit that well for storage of high pressure gas is novel is characterized in that: be made up of bottom (head) 1, stainless steel plug 2, plug depression bar 3, the second road plug 4, casing coupling 5, sealing ring 6, bolt 7; The bottom of bottom (head) 1 porose 11; The bottom cylinder of stainless steel plug 2 is identical with the diameter in hole 11 and put in the hole 11; The cylinder outer ring, bottom of stainless steel plug 2 is equipped with sealing ring 6, and the middle part of stainless steel plug 2 is tapered, and the upper end of stainless steel plug 2 is connected with bolt 7 with the bottom of plug depression bar 3; The inner ring of plug depression bar 3 is a drum, and sealing ring 10 is installed in the epimere outer ring of plug depression bar 3; The second road plug 4 be shaped as the cylinder hat, the second road plug 4 is socketed in that the upper end of plug depression bar 3 is outside, the top of the second road plug 4 is fixedly connected nut 12, the slip joint casing box cupling 5 in the epimere outer ring of bottom (head) 1.
As shown in Figure 1: device is made up of bottom (head) 1, stainless steel plug 2, plug depression bar 3, the second road plug 4, casing coupling 5, sealing ring 6, bolt 7 etc.
See Fig. 2, the direct circulation cementing method that well for storage of high pressure gas is novel is characterized in that: carry out following steps in order
Step 1, brill vertical shaft; The dark 20-300 rice of vertical shaft;
Step 2, in floor-mounted, vertically after the assembling, the plug depression bar 3 of screwing compresses stainless steel plug 2 in the hole 11 of bottom (head) 1 with bottom (head) 1, stainless steel plug 2, plug depression bar 3, box cupling 5; The second road plug 4 is not installed before the well cementation.
Step 3, carry out the hydrostatic test on ground: connect pipeline on ground and carry out the water pressure testing, the assembly of the bottom (head) 1 that assembles, stainless steel plug 2, plug depression bar 3 is carried out the hydrostatic test, to hydraulic pressure be 33Mpa-42Mpa; Voltage stabilizing 10-50 minute; It is qualified detecting leakproof, if hydraulic pressure is defective, explain that bottom (head) 1 and stainless steel plug 2 are off quality or install defective; Change bottom (head) 1 and stainless steel plug 2, carry out the hydrostatic test after reinstalling until qualified;
Step 4, cementing unit is installed in well, with the assembly of the bottom (head) that assembles 1, stainless steel plug 2, plug depression bar 3 along the shaft bottom of falling under the well head; Carry out casing job then: confirm the number of casing coupling 5 and steel pipe casing coupling 5 to be enclosed within on the bottom (head) 1 according to the degree of depth of well, with steel pipe socket on casing coupling 5, mounting sleeve box cupling 5 and steel pipe step by step in order;
Step 5, make a strength test, mainly detect the intensity of sleeve pipe, water pipe is poured water in well from ground, and progressively being forced into hydraulic pressure is 33Mpa-42Mpa; Voltage stabilizing 3-8 hour, it was qualified that hydraulic pressure does not have pressure drop; If defective, then take out sleeve pipe, casing replacing more is in case gas storage well and sleeve pipe scrap, until qualified;
Step 6, carry out the direct circulation well cementing operation, carry out according to the following steps:
A, the connector 8 of will cementing the well are enclosed within on the plug depression bar 3,
When B, well cementation, rotary drill rod is connected drilling rod with well cementation connector 8; Joint face is at screw thread 81 places, and drilling rod down arrives shaft bottom with drilling rod by root with after well cementation connector 8 is connected; It is fastening that drilling rod is connected, and well cementation connector 8 is a sleeve-shaped, and the upper end of well cementation connector 8 is screw thread 81 connector shapes; During well cementation, with Type B pincers every drilling rod is tightened in the going down process, get into the top such as the shown position of plug depression bars 3, be outside equipped with sealing ring 10 in the well cementation connector 8 and be used for the shutoff cement paste and prevent in the cement paste entering sleeve pipe through well cementation connector 8 front ends guiding 82; Drilling rod is that inwall is cylindrical steel pipe.
C, counter-rotating drilling rod withdraw from stainless steel plug 2 in the bottom outlet 11 of bottom (head) 1; (moving back button length is controlled at about 30mm--60mm; Do not thread off to guarantee plug depression bar 3 and bottom (head) 1), connecting the well cementation pump will grout in, along the diagram direction of arrow; Grout in from the top down and be followed successively by: the bull stick inwall--the outside 23 of the hole 11--bottom (head) 1 of inner chamber 22--bottom (head) 1 bottom of the hole 9--bottom (head) 1 on the inner chamber 31--plug depression bar 3 of the inner chamber 83--plug depression bar 3 of well cementation special joint 8; Until injecting gas storage steel pipe outer annular space, fill whole outer annular space, thereby realize the direct circulation well cementation;
After D, well cementation are accomplished, inject clear water and replace out cement paste in the drilling rod, clean drilling rod and bottom (head) bottom outlet 11; The clear water amount is greater than the drilling rod internal volume; After shutting surface water mud pipeline valve, prevent that cement paste from returning in the drilling rod, is rotated in the forward drilling rod; Tighten plug depression bar 3 to compress stainless steel plug 2, realize sealing for the first time; On carry drilling rod and take out drilling rod, take out well cementation connector 8;
Step 7, sealing for the second time: the plug when the second road plug 4 is 3-5 for specification; Become the conical surface seal plug; Its sealing principle is with sealing for the first time, and its structure is that buckle in the cover pipe range garden when screw thread partly is 3-5; Sealing is high, and the second road plug, 4 front ends are provided with guide end 13 and are not easy thread alternating when guaranteeing to detain; Through drilling rod the second road plug 4 is sent in the well, be rotated in the forward drilling rod, tighten screw thread, moment of torsion meets API moment of torsion standard-required; Because the effect of sealing is for the first time arranged, and cement paste there should be no return in the gas storage steel pipe, therefore guaranteed the cleaning and the sealing effectiveness of screw thread part.
Embodiment 1: be pressurised into 36Mpa in the step 3, voltage stabilizing 10 minutes; Being forced into hydraulic pressure in the step 5 is 37Mpa, voltage stabilizing 4 hours.
Embodiment 2: be pressurised into 40Mpa in the step 3, voltage stabilizing 30 minutes; Being forced into hydraulic pressure in the step 5 is 39Mpa, voltage stabilizing 6 hours.