59results about How to "Improve cementing quality" patented technology

The invention discloses a layered tackifier, belongs to the technical field of oilfield chemistry, and particularly relates to a layered tackifier as well as a preparation method and application thereof, the layered tackifier comprises a layered material and a tackifying material, the layered material is two-dimensional transition metal carbonitride, and the tackifying material is a silicon nitride material. The tackifying material is prepared from the following raw materials: 2-acrylamido-2-methylpropanesulfonic acid, a quaternary ammonium salt monomer and a thermal tackifying monomer. Wherein the tackifying material is a polymer prepared from 2-acrylamido-2-methylpropanesulfonic acid, a quaternary ammonium salt monomer and a thermal tackifying monomer; the layered tackifier is used for improving the suspension stability of high-density cement paste and can meet the high-temperature construction environment of 150-210 DEG C, and the density difference of the cured cement paste after standing for two hours is smaller than 0.03 g / cm < 3 >.

The invention discloses a controllable reaming casing centralizer for a well and a related method. The casing centralizer comprises a centralizer body, a binding rope and a locking device, the centralizer body comprises a first shroud ring, a second shroud ring, a first bow piece and a plurality of second bow pieces; the first bow piece and the second bow pieces are evenly distributed between the first hoop ring and the second hoop ring in the circumferential direction. The middle portions of the first bow piece and the second bow pieces are bent inwards to form bent portions, the locking device is fixed to the inner side of the first bow piece, the binding rope penetrates through the locking device, a through hole is formed in the middle of the first bow piece, and the binding rope penetrates out of the inner side of the first bow piece through the through hole and is bound to the bent portions of the first bow piece and the second bow pieces. The locking device can be unlocked so as to release the binding rope; the casing centralizer improves the centering effect and the well cementation quality of a reaming section casing, solves the problem that a pipe string is difficult to descend, and is simple in structure, low in machining cost, convenient to popularize and apply on a large scale and beneficial to improving economic benefits.

The invention provides an elastic centralizer which comprises a first connecting cylinder, a second connecting cylinder and a plurality of centralizing ribs, the top ends of the centralizing ribs are connected with the first connecting cylinder, the bottom ends of the centralizing ribs are connected with the second connecting cylinder, the first connecting cylinder and the second connecting cylinder are arranged on the outer wall of a sleeve in a sleeving mode, and the centralizing ribs are made of fiber resin composite materials. And the sleeve extends in an arc form in the direction far away from the sleeve. According to the elastic centralizer, the contact area of the centralizing ribs and the well wall is in a proper range, large supporting force can be provided, stress is not concentrated, meanwhile, the centralizing ribs have good elastic reset capacity, when the centralizing ribs are subjected to local pressure, the centralizing ribs are not prone to plastic deformation, and therefore centering running of a casing cannot be affected.

The invention discloses a pressure control well cementation system and method. The system comprises an automatic throttling unit, an automatic slurry supplementing and pressurizing unit and a control center. Wherein the automatic throttling unit is used for being arranged between a well mouth and a mud tank so as to control the back pressure of the well mouth by adjusting the valve opening degree of the throttling valve; the automatic slurry supplementing and pressurizing unit is used for being communicated with a connecting pipeline between a well mouth and the automatic throttling unit so as to control well mouth back pressure by compensating fluid flow for the system. The control center is used for controlling the automatic throttling unit to adjust the valve opening degree of the throttling valve and / or controlling the automatic slurry supplementing and pressurizing unit to adjust the output fluid flow so as to control the back pressure of the wellhead based on the target fluid parameters of the wellhead and the parameter deviation of the corresponding actually-measured fluid parameters. The fluid parameters comprise pressure or fluid flow, and the actually-measured fluid parameters comprise actually-measured pressure of one end, close to the wellhead, of a throttling valve of the automatic throttling unit or actually-measured fluid flow of the output end of the automatic throttling unit. And pressure control in the whole well cementation process can be achieved.

The present invention relates to the technical field of cementing of oil and gas wells, and in particular to a percussion positioning straightener to alleviate the problem that the position of the plug cannot be accurately judged during deep well and ultra-deep well operations. The device includes a casing, a vibration component and a signal transmitting unit; the vibration component is arranged on the side wall of the casing; the vibration component includes a controller and a percussion hammer; the controller is electrically connected to the driving motor of the percussion hammer; when the controller receives the signal of the signal transmitting unit, it can start the driving motor to control the reciprocating motion of the percussion hammer. The signal transmitting unit is arranged in the cementing plug. After the cementing operation is completed, the cementing plug is put into the cementing plug to start the slurry replacement operation. During the falling process of the cementing plug, the controller receives the signal of the signal transmitting unit and controls the percussion hammer to vibrate. After the ground sensor receives the vibration sound wave, it can obtain the position of the plug, which provides a decision basis for on-site construction technicians to solve whether to continue construction when the displacement amount reaches the designed amount without collision pressure during cementing.

The utility model relates to a self-adaptive casing centralizer. According to the technical scheme, the centralizer comprises an inner pipe, elastic centralizing pieces, rigid centralizing strips and springs, clamping plates are evenly distributed on the outer sides of the upper end and the lower end of the inner pipe, channels are formed by the clamping plates and the outer side of the inner pipe, the elastic centralizing pieces are made of elastic materials, and each elastic centralizing piece comprises a middle arching part and straight edge parts at the two ends. The straight edge portions at the two ends of the elastic centralizing piece are inserted into the channel, the rigid centralizing strip is arranged on the outer side of the middle of the inner pipe, the elastic centralizing piece and the rigid centralizing strip are correspondingly arranged, and a spring is arranged between the elastic centralizing piece and the rigid centralizing strip. The casing centralizer has the advantages that the casing centralizer is installed at the design position of a casing string, the centralizer is expanded under the action of spring force according to the condition of a borehole outside a casing, and the casing centralizer is self-adaptive to the actual condition of the borehole outside the casing; by changing the specification and the length size of the spring, different borehole conditions can be adapted.

The invention relates to the technical field of interface reinforcing agent preparation, in particular to an interface reinforcing agent for improving the cementing quality of a well cementation two-interface, a preparation method of the interface reinforcing agent, an interface modification prepad fluid and a preparation method of the interface modification prepad fluid. The raw materials comprise styrene, acrylic acid, acrylonitrile, acrylamide, acrylic acid-2-hydroxyethyl ester, an initiator, styrene, butadiene, an initiator, calcium oxide and deionized water. The interface reinforcing agent for improving the cementing quality of the well cementation two-interface is good in compatibility with drilling fluid, and interface modified prepad fluid obtained by taking the interface reinforcing agent for improving the cementing quality of the well cementation two-interface as a raw material has good suspension stability and filtration loss control capability; the cementing strength of a well cementation interface can be effectively improved, and the cementing quality of the well cementation interface is remarkably improved, so that the purpose of preventing annulus channeling or annulus pressure is achieved.

The invention relates to the technical field of salt-cavern gas storage drilling, in particular to a salt-resistant toughness self-repairing cement paste system for a salt-cavern gas storage and a preparation method of the salt-resistant toughness self-repairing cement paste system. The cement paste system comprises the following components in parts by mass: 65-90 parts of G-grade cement, 10-35 parts of a superfine active material, 4-10 parts of a toughening material, 3-10 parts of a cementing enhancer, 1-5 parts of a salt-resistant fluid loss agent, 0.5-3 parts of a low-temperature early strength agent, 0.1-0.5 part of a high-efficiency dispersant and 0.2-1 part of a defoaming agent, 0.5-5 parts of an expanding agent and 40-48 parts of a semi-saturated NaCl aqueous solution. The cement paste system not only has good salt resistance, elasticity and toughness, but also has the characteristics of micro-expansion, strong cementation, self-repairing and the like, so that the cement paste system is particularly suitable for the salt-cavern gas storage, the well cementation quality of the salt-cavern gas storage can be effectively improved, and the shaft integrity of the salt-cavern gas storage in a frequent strong injection and production period is guaranteed.

The application discloses a salt-resistant water-non-dispersible material for oil well cement and a preparation method thereof. The salt-resistant water-non-dispersible material for oil well cement comprises the following components in the form of weight parts: 100 parts of N,N-dimethyl acrylamide, 3-6 parts of acrylic acid, 10-20 parts of 2-acrylamide-2-methylpropanesulfonic acid, 5-15 parts of a cyclic monomer, 0.1-0.4 parts of a branching agent, 5-15 parts of a cationic monomer, 0.3-3 parts of a crosslinking agent and 400-500 parts of water. The salt-resistant water-non-dispersible material prepared by the application has good salt resistance, can significantly improve the anti-dispersion performance of the cement slurry when used in a salt water and sea water cement slurry system with a NaCl content of 18 wt% or less, and has excellent rheological performance.

This invention belongs to the technical field of cementing devices, specifically relating to a foamed cement slurry cementing device. It aims to solve the problem of uneven foam distribution within the foamed cement slurry that ultimately settles on the wellbore, reducing cementing quality. The invention includes a reinforcement pipe, a delivery pipe, an external wellbore base, a return assembly, a drive assembly, and an injection head. This invention can introduce foamed cement slurry from well sections with higher foam content back into well sections with lower foam content for circulation, thereby ensuring the uniformity of foam distribution and size within the foamed cement slurry during its flow through the delivery pipe and return cavity, thus improving cementing quality.

The invention provides high-temperature-resistant cement for well cementation, a cement paste system and a preparation method of the high-temperature-resistant cement. The high-temperature-resistant cement for well cementation comprises the following components in parts by weight: 40-55 parts of G-grade oil well cement, 40-55 parts of low-calcium portland cement, 1-5 parts of gypsum, 1-10 parts of sulphoaluminate cement and 1-10 parts of a composite admixture. The high-temperature-resistant cement slurry system for well cementation comprises the following components in parts by weight: 100 parts of high-temperature-resistant cement for well cementation, 0-70 parts of quartz sand, 1-6 parts of a suspension stabilizer, 2-9 parts of a fluid loss agent, 0.5-1.5 parts of a dispersing agent, 1-9 parts of a retarder, 0.1-0.5 part of a defoaming agent and 40-100 parts of water. The applicable temperature range of the cement and cement paste system is 150-240 DEG C, the compressive strength of set cement cured for 28 days is larger than 40 MPa, the compressive strength of the set cement does not decline, and the well cementation sealing effect of high-temperature and ultra-high-temperature deep wells and ultra-deep wells is guaranteed.

The application provides a kind of test device and method for evaluating volume change rate of cement slurry in cementing waiting-on-phase, and belongs to the technical field of oil and gas well cementing engineering.The test device comprises a curing kettle body, a cement slurry cup is arranged in the curing kettle body, a supporting assembly is used to suspend the cement slurry cup in the curing kettle body, and an adjusting assembly is used to assist in taking the cement slurry cup.The cement slurry cup can be suspended by the supporting assembly and the adjusting assembly, the remaining space in the curing kettle body forms a continuous flow cavity, which is beneficial to simulate temperature conditions and pressure environment closer to the actual downhole environment, the cement slurry cup can be easily taken out or put into the curing kettle body without the help of additional tools, the operation time is saved, the liquid medium in the cement slurry cup can be easily emptied, and the subsequent processing work after the test is completed is simplified.

The present application belongs to the technical field of drilling, and particularly relates to a hydraulic casing centralizer and a use method thereof. The hydraulic casing centralizer comprises an upper joint and a lower joint. A sliding assembly is slidably connected in the upper joint. An operating plate is connected to one end of the sliding assembly facing the lower joint. A centralizing arm is hingedly connected to one end of the lower joint facing the upper joint. The wedge shape on the operating plate matches the wedge shape on the centralizing arm. A hydraulic separation device and a flow channel are arranged on the sliding assembly. Liquid flows into the space between the sliding assembly and the upper joint through the flow channel. The hydraulic separation device drives the operating plate to move towards the centralizing arm according to the pressure setting value. A limiting assembly is arranged between the sliding assembly and the upper joint to limit the position of the operating plate after movement. The operating plate drives the centralizing arm to rotate and support the well wall by using the wedge shape matching the centralizing arm. The centralizer forces the casing string to be centered in the wellbore, thereby improving the cementing quality.

The invention relates to a wetting reversal agent alkane polyol ether for a drilling fluid as well as preparation and application thereof. The wetting reversal agent alkane polyol ether for the drilling fluid is prepared from ethylenediamine, monohalogenated alkane, 11-dodecenol, ethylene oxide, sodium hydroxide, vinylpyridine, an initiator, normal propyl alcohol and deionized water. The preparation method comprises the following steps: reacting ethylenediamine with monohalogenated alkane to obtain an intermediate product A, reacting 11-dodecenol with ethylene oxide to obtain an intermediate product B, polymerizing the intermediate product B with vinylpyridine to obtain an intermediate product C, mixing the intermediate product A with the intermediate product C, and draining water to obtain the reverse wetting agent alkane polyol ether for the drilling fluid. When the concentration of the reverse wetting agent alkane polyol ether for the drilling fluid is 0.10%, the surface tension of a solution can be reduced to a lower value, and the reverse wetting agent alkane polyol ether for the drilling fluid has very strong adsorbability to the rock surface, can greatly enhance the hydrophilic performance of the rock surface, has good reverse wetting performance, improves the oil extraction efficiency, and is also beneficial to improving the well cementation quality in the later period.

The utility model discloses a reinforced well cementation casing centralizer tool, the main body structure adopts the seamless steel pipe of spring steel, after cutting, the integral main body structure of further processing is formed after the integral processing, the upper sleeve and the lower sleeve of accommodating and sleeving in casing are located in the upper and lower both ends, and the multiple centralizing ribs of longitudinal arrangement between the upper sleeve and the lower sleeve and in the middle part, multiple centralizing ribs are arranged on the outer peripheral surface of upper sleeve and lower sleeve along the circumferential direction of upper sleeve and lower sleeve and are integrally formed connection with upper sleeve and lower sleeve, and the centralizing rib is outwardly inclined from the upper and lower both ends to the axis of casing, and a stress groove is arranged in the middle position of each centralizing rib to increase the reset force after deformation, and the fluid flow channel is formed between the adjacent two centralizing ribs, and the brush is fixed on the outside of upper sleeve and lower sleeve, and the brush is in contact with the well wall to destroy and remove the well wall mud cake. The application can ensure that the casing can smoothly enter the well, and improve the well cementation quality.

The invention relates to the technical field of oil field workover treatment, in particular to a heavy oil thermal production well tail pipe fixing process for workover treatment. The process comprises the following steps that according to physical property characteristics, combination, distribution and section lengths of different stratums, corresponding composite cement paste is selected and prepared for well cementation, and the composite cement paste comprises plugging cement paste, thixotropic cement paste, high-density cement paste and conventional cement paste. According to the method, well cementation cement paste with different properties is selected in a targeted mode for well cementation according to different well conditions and overall distribution and section lengths of different stratums, and the well cementation quality is good.

The invention relates to the technical field of oil and gas well drilling and completion, in particular to a pressure control method for well cementation operation, a sealing device and application of the sealing device, and the pressure control method comprises the steps that in the well cementation operation process, whether overflow occurs or not is judged; if yes, the shut-in casing pressure is calculated; the equivalent mud density or the equivalent completion fluid density for balancing the formation pressure is calculated according to the shut-in casing pressure, and the needed equivalent wellhead return pressure is calculated; annular sealing of the wellhead is kept, and the equivalent wellhead return pressure obtained through calculation in the above step is maintained at the wellhead by controlling the opening degree of a throttling valve; and the slurry density or the well completion fluid density is gradually increased, the opening degree of the throttling valve is correspondingly controlled, and the well cementation operation process continues. By means of the pressure control method, the sealing device and the application of the pressure control method, the sealing device and the sealing device, the annulus pressure profile of a shaft can be controlled in the well cementation operation, manual intervention on downhole pressure abnormity in multiple links such as casing running and well cementation can be achieved, the well control risk of the well cementation operation is greatly improved, and the well cementation operation quality is improved.

The application discloses a high-temperature-resistant expanded fiber resin plugging material and a preparation method and application thereof in leakage prevention and plugging of well cement slurry. The preparation method of the high-temperature-resistant expanded fiber resin plugging material comprises the following steps: S1, adding sodium hydroxide into an acrylic acid solution, and then adding a chitosan solution, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and fibers into the acrylic acid solution in sequence; and then adding an initiator and a crosslinking agent into the acrylic acid solution in sequence, and obtaining a polymer gel through polymerization; the chitosan solution adopts glacial acetic acid solution as a solvent; and the polymer gel is dried and then crushed to obtain a granular resin. Through use of the high-temperature-resistant expanded fiber resin plugging material, the problem of cement slurry leakage in a fractured formation can be effectively solved, the treatment time and cost of cement slurry leakage in the fractured formation are greatly reduced, and the cementing quality of the fractured formation is improved, thereby opening up a new way for solving the problem of cement slurry leakage in the fractured formation.

The invention provides high-density cement paste as well as a preparation method and application thereof. The high-density cement paste disclosed by the invention is prepared from the following components in parts by mass: 2 to 4 parts of dispersing agent PC-F45L, 1.2 to 1.5 parts of retarder PC-H40L, 5.5 to 6 parts of fluid loss agent PC-G80L, 0.5 to 1 part of defoaming agent, 38 to 42 parts of weighting agent, 98 to 102 parts of cement and 220 to 246 parts of water. The dispersing agent, the retarder and the fluid loss agent are specifically selected and compounded with other components, so that the obtained high-density cement paste cannot be thickened too early (the thickening time exceeds 400 minutes) in the grouting process, has better strength, sedimentation stability, rheological property and filtration loss property, and can well improve the well cementation quality.

The invention belongs to the field of oil and gas well cementation and oilfield chemistry, and particularly relates to a curing liquid for improving the cementation quality of oily well wall interface cementation and application thereof, the curing liquid comprises the following raw materials by weight: 100 parts of oil well cement, 1 part of a fluid loss agent, 1-2 parts of an enhancer, and 44 parts of water; the interface reinforcing agent is a mixture of a silane coupling agent KH560, sodium methyl silicate and Tween 60, the oily well wall is an oil-based drilling fluid drilling well wall or a coal rock well wall, the curing liquid contains a special reinforcing agent, and the cementing quality of the curing liquid and the oily well wall is obviously superior to that of conventional oil well cement paste; the problem that the enhancement effect is lost after a traditional enhanced prepad fluid modified oily well wall interface is scoured by oil well cement paste is solved; the problem that oily well wall interface modification cannot meet requirements due to prepad fluid leakage is avoided, and the problems that oil well cement paste is too long in setting time and slow in strength development after a traditional interface reinforcing agent is added into the oil well cement paste are solved.

The invention discloses a core-shell slow-release tackifier and a preparation method and application thereof, and relates to the technical field of oilfield chemistry, the core-shell slow-release tackifier comprises a core material and a shell material, the core material is prepared from a raw material I comprising 2-acrylamido-2-methylpropanesulfonic acid (AMPS), acrylic acid (AA), a hydrophobic monomer and hectorite; the shell material is prepared from a raw material II comprising a styrene monomer; the core-shell slow-release tackifier with the thermal tackifying effect is used as a suspension stabilizer of high-density cement paste, and can meet the high-temperature construction environment of 150-210 DEG C, and the density difference of the cured cement paste after standing for two hours is less than 0.03 g / cm < 3 >.

A cementing isolation fluid composition comprises the following components, measured by mass and weight: 100 parts of water; 30-50 parts of an intelligent responsive amphiphilic block copolymer; 5-10 parts of modified nanocellulose; 2-5 parts of a bifunctional crosslinking agent; 10-15 parts of an environmentally friendly surfactant; 100-200 parts of a nanocomposite weighting agent; and 1-3 parts of a slow-release antioxidant. Through the synergistic effect of the intelligent responsive amphiphilic block copolymer and the modified nanocellulose, the isolation fluid can still maintain good rheological properties under the conditions of 200°C and 100MPa, and the apparent viscosity reduction is less than 20%. The PNIPAM block provides temperature responsiveness, the PDEAEMA block provides pH responsiveness, and the PSS block provides salinity responsiveness, so that the isolation fluid can adaptively adjust its structure and performance according to the downhole environment.

The invention discloses a well cementation cement slurry system with low permeability, elasticity and toughness, which comprises the following components in parts by weight: 100 parts of oil well cement, 35.6 parts of water, 4-6 parts of a fluid loss agent, 4-6 parts of a reinforcing agent, 2-3 parts of an expanding agent, 0.3-0.5 part of a retarder, 0.5-1 part of a dispersing agent, 0.5-1 part of a defoaming agent, 0.5-1 part of polypropylene fiber, 10-15 parts of latex and 0.5-1 part of a latex stabilizer. The length of the polypropylene fiber is 8-10 mm, and the equivalent diameter of the polypropylene fiber is 32-36 [mu] m; the latex is styrene butadiene rubber latex, the latex is an emulsified polymer, spherical polymer particles in the latex exist in an emulsion suspension form, and the particle size is 0.05-0.5 mu m; the latex stabilizer is a surfactant stabilizer; the invention further discloses a preparation method. The improvement on the fluidity, the toughness, the anti-permeability and other properties of the cement paste is realized.

The present invention is a side-drilling large-diameter casing straightener and its completion pipe string and construction method. The casing straightener in the present invention includes an upper joint, a center pipe and a lower joint. The cylinder body of the straightening cylinder is a rib-shaped cylinder body. The straightening cylinder and the driving cylinder are sleeved on the outside of the center pipe. The timing limit cylinder is installed between the center pipe and the lower joint. The upper part of the center pipe is connected to the upper joint, the lower part of the driving cylinder is connected to the lower joint, and the timing limit cylinder is squeezed between the center pipe and the lower joint. The completion pipe string in the present invention is provided with a floating shoe, a floating hoop and a casing hydraulic hanger. The floating shoe, the floating hoop and the casing hydraulic hanger are connected by casing from bottom to top and lowered into the bottom of the side-drilling well by a drill pipe or an oil pipe. In the completion pipe string above the floating hoop, the side-drilling large-diameter casing straightener is connected by casing according to the design requirements of the completion pipe string. The process of the present invention is simple and reliable, effectively prolongs the service life of the side-drilling well and can produce significant economic benefits.

This invention discloses a tailpipe cementing annulus pressure-holding tool and its usage method, belonging to the field of tailpipe cementing technology. The tailpipe cementing annulus pressure-holding tool includes: an upper connector, a valve control unit, a valve plate, a valve seat, and a lower connector; the upper connector and the lower connector are fixedly connected; the valve control unit is slidably disposed inside the upper connector and the lower connector, and the valve control unit abuts against the upper connector and the lower connector respectively; one end of the valve control unit abuts against one side wall of the valve plate; the valve plate is rotatably connected to the valve seat; the valve seat is sleeved inside the lower connector, and the outer wall of the valve seat abuts against the inner wall of the lower connector; the valve seat is tubular, with two V-shaped grooves symmetrical about the center of the valve seat on its side wall. The tailpipe cementing annulus pressure-holding tool of this invention has a simple structure, reliable function, and is applicable to tailpipe cementing operations of most casing types, effectively improving cementing quality.

The invention relates to low-density cement paste which comprises the following components in parts by weight: 100 parts of cement; 15 to 20 parts of micro silicon; 23 to 27 parts of microbeads; 2-4 parts of a suspending agent; 4-7 parts of a fluid loss agent; 2 to 3 parts of a retarder; 2-3 parts of a drag reducer; 0.1 to 0.2 part of a defoaming agent; and 80 to 85 parts of water. The cement paste has the advantages that the cement paste is fast in cement feeding, good in rheological property, good in stability at high temperature, excellent in water loss and fast in compressive strength development, and the cement paste is high in well cementation quality and high in operation efficiency.

This invention discloses a cement sheath micro-gap pressure testing device, method, data, medium, and application, relating to the field of oil and gas well sealing technology. It includes an outer casing and an inner casing, with the outer casing fitted over the outer side of the inner casing, forming an annular cavity between them; a sealing element that seals the inner cavity of the inner casing; a pressure injection system connected to the inner cavity of the inner casing; a pressure control system connected to the pressure injection system; an acoustic logging tool housed within the inner cavity of the inner casing; a logging control system connected to the acoustic logging tool; a micro-gap size acquisition system; and a data association system. This invention can simulate the generation and evolution process of cement sheath micro-gap under varying downhole pressure conditions, establish a calibration relationship between acoustic response and micro-gap state, and provide experimental basis for evaluating cement sheath sealing integrity and optimizing cementing quality.

The application discloses a casing centralizer for controllable reaming well and a related method. The casing centralizer comprises a centralizer body, a binding rope and a locking device. The centralizer body comprises a first hoop ring, a second hoop ring, a first bow piece and a plurality of second bow pieces. The first bow piece and the plurality of second bow pieces are uniformly distributed between the first hoop ring and the second hoop ring in a circumferential direction. The middle part of the first bow piece and the second bow piece is inwardly bent to form a bent part. The locking device is fixed to the inner side of the first bow piece. The binding rope passes through the locking device. The middle part of the first bow piece is provided with a through hole. The binding rope passes through the through hole from the inner side of the first bow piece and is bound to the bent part of the first bow piece and the plurality of second bow pieces. The locking device can be unlocked to release the binding rope. The casing centralizer improves the centering effect of the casing in the reaming section and the cementing quality, solves the problem of difficult pipe string running in, has a simple structure, low processing cost, is convenient for large-scale popularization and application, and is favorable for improving economic benefits.

The invention discloses a well cementation method and a well cementation system suitable for a surface casing interpolation method. The well cementation method and the well cementation system solve the problems that an existing well cementation method is inconvenient to operate, low in production efficiency, high in cost and prone to slurry mixing. The well cementation system comprises an underground part and an overground part, the underground part comprises a guide pipe inserted into a well wall stratum and a surface casing string inserted into a well, and the overground part comprises a cement supply system and a drilling fluid circulation system. According to the method, the drilling fluid is injected firstly to stabilize the flow, then the cement paste is injected, and finally the drilling fluid is injected to replace the cement paste in the drill rod string. The method is easy to operate, the length of the cement plug can be controlled, slurry mixing is avoided, and the well cementation quality is good; the system is simple, easy to operate and low in production cost and equipment cost.

The invention relates to a deepwater and ultra-deepwater well cementation multifunctional vibration guiding shoe which comprises a radial vibration module and a rotor module, the radial vibration module comprises a stator core shaft, rupture disk assemblies and a rotor assembly, the stator core shaft is of a hollow cylindrical structure with the two ends open, and the rupture disk assemblies are arranged in an inner cavity of the stator core shaft at intervals; the rotor assembly is arranged on the outer wall of the stator core shaft in a sleeving mode, and the stator core shaft is provided with a plurality of flow channels which are in fluid conduction connection with the rotor assembly. The rotary drum is arranged on the outer wall of the stator core shaft in a sleeving mode and located outside the rotor assembly, and the eccentric guide shoe is assembled on the rotary drum and located at the downstream end of the stator core shaft; the axial vibration module comprises an eccentric block, the eccentric block is arranged in the eccentric guide shoe, and an eccentric hole is formed in the eccentric guide shoe. The device can effectively improve the well cementation operation efficiency and quality, and is suitable for well cementation construction under various complex working conditions.