3129 results about "Drilling fluid" patented technology

Methods of operating candle filter systems for removing solids from MEG recovered from drilling fluids include passing an MEG rich stream to a candle filter system comprising a plurality of candle filter units in parallel, determining a concentration of TDS in the MEG rich stream, determining whether to operate the candle filter system in a low TDS mode or a high TDS mode based on the concentration of TDS the MEG rich stream, filtering the MEG rich stream in the plurality of candle filter units to produce a filtrate and a filter cake, determining to conduct a cleaning cycle of the candle filter units based on a pressure differential, and conducting a cleaning cycle to remove the filter cake from the outer surfaces of the filter candles. The cleaning cycle is modified to improve removal of solids from the filter candles of the candle filter units.

The invention discloses a radioactive measurement data processing method for improving uranium exploration efficiency. The method comprises the following steps: standardized data acquisition: integrating a multi-parameter module, carrying out time-space synchronous acquisition of geological geophysical environment parameters, standardizing protocol alignment data, and supporting three-dimensional modeling; a three-dimensional coupling model is used for processing interference in a sub-module mode, LiDAR-DEM is used for correcting gamma attenuation in the terrain, an optical fiber thermopermeability instrument is used for correcting daughter errors in the hydrology, signal attenuation of a borehole is compensated through a drilling fluid chart, and a space-time continuous interference field is formed; performing dynamic equilibrium coefficient inversion: constructing equilibrium coefficient isoparametric mapping, and inputting rock core, logging and geochemical data into a random forest model; the transfer learning is trained by using historical data, and dynamic inversion and updating of a new area are carried out; intelligent data processing three-dimensional visualization: self-adaptive denoising and spectral shape matching reinforcement abnormity are carried out; constructing a three-dimensional model, and carrying out transfer learning to optimize the precision; the WebGL platform integrates multi-parameter display, virtual drilling functions and high-dimensional data intuitive interpretation.

The invention relates to a shale oil borehole wall collapse pressure prediction method. The method comprises the following steps: acquiring components, structures and physicochemical properties of a shale oil reservoir; carrying out soaking-nuclear magnetism-sound wave-triaxial stress combined measurement experiments of different drilling fluid systems; constructing a shale oil reservoir rock heterogeneous water absorption and strength degradation equation; establishing ground stress and pore pressure profiles; converting the far-field crustal stress into a borehole and bedding coordinate system; calculating a well periphery stress field generated by water absorption of the surrounding rock; simulating and calculating the temperature field distribution of the rock and calculating a thermal stress value; the well periphery stress value under the force-chemical-thermal-bedding coupling effect is calculated in a superposition mode; constructing a well surrounding rock matrix and weak plane shear failure discrimination function and condition; constructing a shale oil reservoir collapse pressure numerical simulation iterative trial algorithm; determining a formation collapse pressure density control factor and a control mechanism; and the shale oil borehole wall collapse risk is reduced through optimization. According to the method, the shale oil borehole wall collapse pressure under the force-chemical-thermal-bedding coupling effect can be predicted more accurately.

The invention relates to the technical field of drilling fluids, and discloses a lignite-based modified filtrate reducer for a drilling fluid and a preparation method of the lignite-based modified filtrate reducer. The lignite-based modified filtrate reducer for the drilling fluid is obtained by stirring and mixing the lignite grafted copolymer, the hydroxy propyl cellulose and the graphene oxide, drying and crushing. The steric effect generated by an oxazine ring, a pyridine ring, a triazine ring, a benzene ring and a pyrrole ring grafted into the lignite improves the temperature resistance and salt resistance of the filtrate reducer; the dispersing capacity of clay particles in a drilling fluid system is improved through sulfonic acid hydrated groups, and high-temperature coalescence of drilling fluid clay due to the high-temperature effect is avoided; a sulfonic acid anion group and a quaternary ammonium salt cation group are introduced into the filtrate reducer at the same time, so that the filtrate reducer can form a salt internal bond under the action of electrostatic force, and the salt resistance of the filtrate reducer is improved; the nano silicon dioxide increases the rigidity of the filtrate reducer, so that the filtrate reducer is not easy to curl under the conditions of high temperature and high salt.

The invention provides a temperature-resistant and salt-resistant cross-linking tackifying filtrate reducer for a soil-phase-free water-based drilling fluid as well as a preparation method and application of the temperature-resistant and salt-resistant cross-linking tackifying filtrate reducer, and belongs to the technical field of drilling. The temperature-resistant and salt-resistant cross-linking tackifying filtrate reducer for the soilless phase water-based drilling fluid comprises the following raw materials in parts by weight: N, N-dimethylformamide, a cross-linking agent and a cross-linking agent, the invention relates to a water-based adhesive which is prepared from the following components in parts by weight: 15 to 25 parts of N, N-dimethylacrylamide, 1 to 10 parts of 3-[(3-methacrylamidopropyl) dimethylammonium] propane-1-sulfonate, 1 to 10 parts of long-chain alkyl polyoxyethylene ether methacrylate, 0.005 to 0.015 part of macromolecular cross-linking agent, 0.03 to 0.08 part of initiator A and 80 to 100 parts of deionized water. The tackifying filtrate reducer can resist the temperature of 180 DEG C, can resist NaCl to be saturated, has excellent tackifying, shear-improving and filtrate-reducing effects under high-temperature and high-salt conditions, improves the rheological property and the filtrate-reducing property of drilling fluid, and ensures safe and efficient drilling of a deep well.

The invention relates to the technical field of oil and gas well drilling, in particular to an experimental system for measuring the dielectric constant of drilling fluid, which comprises a reaction kettle body, a pressure unit, a temperature unit and a dielectric constant sensor. In the oil-gas well drilling operation process, whether the overflow phenomenon occurs in an oil-gas well or not is judged by monitoring the fluctuation of the dielectric constant of drilling fluid in real time, but the fluctuation of the dielectric constant can also be caused by changes of physical conditions such as pressure and temperature of the drilling fluid, and if the fluctuation of the dielectric constant caused by the changes of the physical conditions is not eliminated, the overflow phenomenon is judged. If so, the accuracy of overflow monitoring is influenced. In the application, the pressure unit and the temperature unit are used for respectively changing the pressure and the temperature of the drilling fluid so as to obtain the change relationship between the pressure and the temperature of the drilling fluid and the dielectric constant; therefore, whether the fluctuation of the dielectric constant of the drilling fluid in the oil and gas well is caused by the change of physical property conditions such as pressure and temperature or not is judged according to the change relation, and the accuracy of overflow monitoring is further improved.

The invention provides sulfonated cellulose. The sulfonated cellulose is obtained by etherifying alkalized cellulose with water-soluble halogenated sulfonate. Compared with the prior art, the sulfonated cellulose provided by the invention contains sulfonic acid groups, hydroxyl groups and other groups, so that when the sulfonated cellulose is used in the drilling fluid, the filter loss of the drilling fluid can be effectively controlled, and meanwhile, the salt pollution resistance, especially the calcium ion pollution resistance, of the drilling fluid can be improved; in addition, sulfonic groups in the product are also beneficial to improving the thermal stability of the drilling fluid, and the application range is expanded. In a word, compared with carboxymethyl cellulose for drilling fluid, sulfonated cellulose provided by the invention has obvious temperature resistance and high-valence metal ion resistance.

The invention discloses a nano blocking agent for drilling fluid and a preparation method thereof, and belongs to the technical field of blocking agents, the nano blocking agent for drilling fluid is prepared by reaction of a core layer blocking agent and a shell layer blocking agent, the core layer blocking agent is prepared by reacting nano silicon dioxide, gamma-methacryloxypropyltrimethoxysilane and a first part of vinylphosphonic acid, and has secondary blocking capability; and the shell blocking agent is prepared by reacting a second part of vinyl phosphonic acid, styrene and 2-dodecene-1-yl succinic anhydride, and has the characteristic of flexibility. The nano plugging agent has rigid supporting and flexible deformation capabilities, and the high-temperature stability and compressive strength of a plugging layer are remarkably improved. The chemical binding force of the plugging agent and the rock is enhanced; the hydrolysable methoxyl reserved in the core layer provides a secondary plugging function, and the plugging validity period is prolonged. The invention relates to a preparation method of a nano blocking agent for drilling fluid, which is used for preparing the nano blocking agent for drilling fluid.

The invention discloses a stepped treatment process for multi-path recycling of oil and gas field drilling mud, which comprises the following steps: oxidizing and breaking gel of the drilling mud to scatter the mud structure, and then granulating and coagulating; then, carrying out the following gradient treatment: step 1, filtering the outlet water of granulation and coagulation, and taking the filtrate as reinjection water; step 2, carrying out nucleation granulation reaction on the filtrate obtained in the step 1, using effluent for preparing drilling fluid, and carrying out solid waste treatment on solid-phase crystal seeds and solid-phase mud cakes subjected to granulation and coagulation; and step 3, carrying out ozone flotation reaction on the effluent obtained in the step 2, wherein the effluent is used for preparing the guanidine gum fracturing fluid. According to the method, resource recycling of the waste drilling mud is achieved, the usage amount of a gel breaker in a traditional gel breaking and filter pressing technology is reduced, a filter pressing plate is omitted, the treatment efficiency in the mud recycling treatment process is improved, the treatment cost of the waste water-based drilling mud is reduced, different recycling ways can be met, and the method is suitable for popularization and application. And specific operation is flexible and changeable.

A method for determining drilling fluid properties. The method includes obtaining current drilling fluid properties for a drilling fluid used in a drilling operation, obtaining operational parameters related to the drilling operation, and obtaining a treatment, wherein the treatment describes one or more additives or processes to be applied the drilling fluid. The method further includes processing the current drilling fluid properties, the operational parameters, and the treatment with a treatment prediction system to determine a prediction for drilling fluid properties after treatment. The method further includes applying the treatment to the drilling fluid and using the drilling fluid, after application of the treatment, in the drilling operation.

The invention relates to a preparation method and application of an inner-rigid outer-soft core-shell structure silicon dioxide blocking agent for marine drilling fluid, and belongs to the field of deepwater oil and gas drilling. N-vinyl-2-pyrrolidone, dimethyl diallyl ammonium chloride, acrylamide and 2-acrylamide-2-methylpropanesulfonic acid are polymerized and grafted on the surface of nano silicon dioxide to form the silicon dioxide blocking agent with a core-shell structure and a rigid inside and a soft outside; by means of rigid plugging of a nano material and deformation filling flexible plugging of a high-molecular polymer, shale micro-nano pores are efficiently plugged with rigid inside and flexible outside, so that the stability of a well wall is maintained, meanwhile, secondary generation of hydrates is effectively inhibited, and the safety and efficiency of deepwater drilling are improved; the plugging agent provided by the invention reduces the demand on a large number of thermodynamic inhibitors, not only saves the cost, but also has the characteristic of environmental protection.

The invention provides an underwater ultrasonic Doppler real-time analysis method and device based on a digital transducer, and relates to the technical field of data analys.The method comprises the steps that 1, multiple beams of directional ultrasonic waves are emitted into drilling fluid through a digital transducer array on the outer wall of a marine riser, echo signals reflected by gas-liquid two-phase flow are received, and the digital transducer array is used for receiving the echo signals; performing real-time digital conversion on the echo signal to generate an original digital signal containing phase and amplitude information; 2, Doppler frequency shift feature extraction is conducted on the original digital signals, and the real-time movement speed and direction of bubbles in the drilling fluid are determined by calculating the frequency deviation of reflected ultrasonic waves and transmitted ultrasonic waves. Through the digital transducer array and the ultrasonic Doppler technology, accurate measurement of motion parameters of bubbles in drilling fluid, real-time calculation of local gas content and early warning and grading response of gas cut are achieved, and the safety and the intelligent level of drilling operation are improved.

The invention discloses a drilling trajectory real-time dynamic tracking control method and system based on deep learning, and relates to the technical field of petroleum drilling, and the method comprises the steps: generating well trajectory control parameters according to the basic information of a well and preset well trajectory data; setting an optimal drilling fluid performance parameter corresponding to the current working condition according to the stratum environment where the drilling tool is located; deep learning is conducted on the well track control parameters and the optimal drilling fluid performance parameters through the correlation model, a drilling parameter setting scheme is generated, and an underground drilling tool is controlled to conduct drilling; comparing the drilling data with data in the drilling parameter setting scheme, and determining deviation in the drilling data; and determining a corresponding fault mode, and determining a corresponding solution from the solution library to correct the drilling parameter setting scheme. According to the method, deep learning is carried out on geological conditions and historical data, the well trajectory control model and other models are constructed, the model can be continuously updated and optimized along with data accumulation, and the drilling trajectory tracking and control precision is continuously improved.

The invention provides a supramolecular hydrogel packer constructed by interaction of a subject and an object as well as a preparation method and application of the supramolecular hydrogel packer, and belongs to the technical field of drilling fluid packing. The supramolecular hydrogel packer constructed by interaction of the subject and the guest comprises the following raw materials in percentage by mass: 12-36% of a copolymerization monomer, 6-10% of a tannic acid grafted polysaccharide aqueous dispersion, 0.5-1.5% of an initiator, 0.3-0.6% of a cross-linking agent and the balance of water, the total amount of the components is 100%. The raw materials are cheap, easy to obtain, simple in composition, low in cost, green, safe and environment-friendly; the preparation method is simple, mild in condition and easy to implement. After crosslinking, the obtained packer has excellent mechanical properties, temperature and pressure resistance and outstanding pH degradation capability, and can effectively pack a crude oil reservoir to form an integral sealing interlayer, so that heavy oil entering a shaft is reduced; meanwhile, degradation of the hydrogel can be effectively realized, and deblocking is achieved.

The invention provides a salt-responsive temperature-resistant salt-resistant water-based drilling fluid tackifying filtrate reducer as well as a preparation method and application thereof, and belongs to the technical field of drilling. The tackifying filtrate reducer is prepared from the following raw materials in parts by mass: 30 to 50 parts of 1-(2-carboxyethyl)-2-vinylpyridine, 20 to 40 parts of (3-(methacrylamido) propyl) dimethyl (3-thiopropyl) ammonium hydroxide inner salt, 35 to 55 parts of N, N-dimethylacrylamide, 10 to 25 parts of 4-vinylpyridine, 300 to 500 parts of water and 1 to 5 parts of an initiator. According to the filtrate reducer, cations and anions are concentrated on one monomer molecule, so that the synthesized product contains the cations and the anions with the same charge number, has good adsorption capacity and salt response characteristics, is compatible with salt essentially, can effectively resist high temperature and high salt, and can be recycled. And the viscosity-increasing and filtrate-reducing agent has good viscosity-increasing and filtrate-reducing effects on the drilling fluid.

The present disclosure relates to the technical field of drilling fluid, and discloses a high density environmentally friendly polymer water-based drilling fluid with resistance to 240° C. and saturated salts, a preparation method therefor and use thereof. The water-based drilling fluid comprises a micro-crosslinked heterocyclic polymer filtrate reducer, a hyper-branched strongly adsorbed filtrate reducer, a nanometer intercalated complex shearing potentiator, a flexible outer and rigid inner microsphere plugging agent, and water, wherein the micro-crosslinked heterocyclic polymer filtrate reducer is prepared by reacting sodium p-styrene sulfonate, N,N,N-trimethyl-3-(2-methylallylamino)-1-propyl ammonium chloride, N,N-diethyl acrylamide, N-vinyl caprolactam, tetramethyl ethylenediamine with phenyl triethoxy silane. The high density environmentally friendly polymer water-based drilling fluid with resistance to 240° C. and saturated salts of the present disclosure can exhibit good performance at high temperature and high salinity conditions, and has desirable weighting capability, it can meet the requirements of drilling well in the deep oil and gas formations.

In one embodiment, the disclosure provides a method on a drilling fluid. The method may include acquiring data from each of a particle-size analyzer, x-ray fluorescence instrument, a mud check, and optionally an x-ray diffraction instrument, to yield acquired data for each of a plurality of drilling mud samples, wherein: (a) the particle size analyzer measures a plurality of drilling mud samples; (b) the x-ray fluorescence instrument and the x-ray diffraction instrument measure a mineral analysis of the plurality of drilling mud samples; and (c) the mud check measures properties of the plurality of drilling mud samples. Further, the method may include plotting a particle size distribution curve for at least one of the plurality of drilling mud samples, and calculating an amount of abrasive formation material(s) within at least one of the plurality of drilling mud samples. Further still, the method may include adjusting the drilling fluid.

The invention relates to the technical field of drilling fluid cooling, and discloses a phase change microcapsule suitable for drilling fluid cooling and a preparation method thereof.The phase change microcapsule comprises a capsule wall stabilizing material and a capsule core phase change material, and the capsule wall stabilizing material comprises polyurethane, polyurea, polyamide, polyimide, polystyrene and a first organic solvent; the capsule core phase change material comprises paraffin, fatty acid, polyol, inorganic hydrated salt, polymer gel, expanded graphite, carbon nanotubes, metal nanoparticles and a second organic solvent, and the first organic solvent is at least one of toluene, xylene, cyclohexanone and the like. The temperature of the drilling fluid is kept at a relatively low level, the cooling of the drilling fluid is realized, so that the drilling efficiency is improved, harmful solvents and additives are not used in the preparation process of the phase-change microcapsules, the phase-change microcapsules are pollution-free to the environment, and the requirements of greenness and environmental protection are met.

A milling bit valve is disclosed for improved debris collection within a wellbore. The check valve can be part of a debris removal tool that includes a motor, pump, gearbox, bailer, milling bit, check valve, and rotational shafts. In an example, on its uphole end, the milling bit can be coupled with the check valve. On its downhole end, the milling bit can be configured for debris removal with cutting edges. The downhole end can also include openings that provide access to an internal cavity of the milling bit. The internal cavity can extend the entire length of the milling bit. This allows the pump to pull drilling fluid into the bailers through the milling bit and check valve. As a result, the debris removal tool can simultaneously remove obstructions in a wellbore and collect debris from the obstruction removal.

Shown and described herein is a choke assembly for use with a downhole drill string. The choke assembly may include a rotating choke carrier, a stationary seat disposed on the rotating choke carrier and a rotating choke positioned adjacent to the stationary seat to create a seal surface. The choke assembly may further comprise a biasing mechanism applying a biasing force to press the rotating choke against the stationary seat and a flow port within the stationary seat which controls drilling fluid to allow some drilling fluid to become a bypass fluid and pass through the stationary seat.

The utility model provides an efficient drill bit for a mine drilling machine, which belongs to the technical field of drill bits and comprises a drill rod and a drill bit body arranged on the drill rod, a flange ring is mounted on the outer wall of one end of the drill rod, and a fixing seat is arranged at one end of the drill rod. According to the utility model, the crushing teeth arranged on the drill bit body are matched with the buffer springs, so that the positions of the crushing teeth can be effectively and automatically adjusted according to the hardness of external rocks and the drilling pressure, thereby reducing greater abrasion of the crushing teeth caused by hard rocks or abnormal loads, prolonging the service life of the drill bit, and improving the drilling efficiency at the same time; the spiral blade arranged outside the drill rod close to one end of the mounting seat continuously lifts the waste drilling fluid between the drill rod and the well wall in the process of synchronously rotating along with the drill rod, so that rock debris can be quickly and effectively removed from a drill hole, and the rock debris is prevented from being accumulated at the bottom of a drill bit to reduce the rock breaking efficiency; meanwhile, friction between the drill bit and rock is reduced, abrasion of the drill bit is reduced, and the drilling effect of the drill bit is improved.

The invention belongs to the technical field of drilling fluid, and particularly relates to a free radical polymerization water-based drilling fluid composition and a preparation method thereof. The invention relates to a core-shell composite particle-containing water reducer which comprises deionized water, salts (NaCl / KCl), alkalis (Na2CO3 and NaOH), barium sulfate and core-shell composite particles X. The particle is composed of a silicon dioxide core and a polymer shell layer, and the shell layer is formed by free radical copolymerization of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and acrylic acid and is covalently connected with the core through silanization treatment. Under the conditions of high salinity, strong alkali and high solid phase weighting, the drilling fluid simultaneously realizes the following effects: (1) high-density bearing and low-viscosity pumpability are realized; (2) compact plugging and water loss reduction and low formation damage flowback can be realized; and (3) stable rheology rock carrying, lubrication and friction resistance reduction. The problem that three aspects of performance are difficult to consider in the prior art is solved, and the drilling fluid is suitable for drilling of deep wells, ultra-deep wells and complex stratums and has remarkable industrial application value.

The invention relates to a preparation method and application of high-temperature-resistant organic modified bentonite. According to the method, three organic modifiers of long-chain quaternary ammonium salt, amide and a silane coupling agent are compounded to modify bentonite, and the problem that a single modifier is easy to decompose at high temperature is solved through the synergistic effect of physical intercalation, chemical crosslinking and interface bonding; and secondly, a three-dimensional stable structure is constructed by adding nano silicon dioxide and a composite modifier, so that the high temperature resistance and dispersion stability of the modified bentonite are further enhanced. According to the invention, the requirements of deep well and ultra-deep well drilling fluids on the temperature resistance and rheological property of the treating agent can be met, and the ultra-deep well drilling fluid which can tolerate the high temperature of 250-300 DEG C, and is low in filter loss and good in dispersion stability can be obtained.

The invention belongs to the technical field of overflow monitoring and judgment in the petroleum and natural gas drilling process, and discloses an overflow monitoring device and method based on a shaft multiphase flow flowing rule. A simulation switch connected with an overflow simulation device is arranged at the bottom of a simulation shaft, and gas invasion, water invasion and oil invasion can be simulated respectively; electromagnetic flow meters are installed on a wellhead drilling fluid injection manifold and a wellhead drilling fluid return manifold respectively, a liquid level pressure sensor is installed in a mud pit, dynamic change data of the electromagnetic flow meters and the liquid level pressure sensor are monitored and obtained in real time through a monitoring machine and stored, analyzed and processed in real time, and characteristic parameters of different types of overflow are determined. And on the basis, overflow monitoring and judgment are carried out, and theoretical support and guidance are provided for field well control operation. The whole device disclosed by the invention does not monitor underground, does not need expensive hardware equipment, is low in investment and operation and maintenance cost, is not limited by underground complex environmental factors, and can avoid signal transmission power loss and improve the monitoring effect.

The invention provides a foundation soil slurry quality analysis method, system and equipment and a storage medium, and relates to the technical field of soil slurry detection. The method comprises the following steps: acquiring multi-modal data of liquid at a drilling fluid inlet and a flow-back liquid outlet by utilizing multi-modal sensors arranged at the drilling fluid inlet and the flow-back liquid outlet; preprocessing the multi-modal data to obtain preprocessed multi-modal data, and performing feature extraction on the preprocessed multi-modal data to obtain multi-modal feature data; and according to the multi-modal characteristic number, extracting the quality parameters of the foundation soil slurry to obtain the quality parameters of the foundation soil slurry, and according to the quality parameters of the foundation soil slurry, analyzing the quality of the foundation soil slurry to obtain a quality analysis result of the foundation soil slurry. Through the alternative scheme, the effect of the pension service is improved.

The invention provides composite anionic cellulose ether as well as a preparation method and application thereof. The composite anionic cellulose ether is prepared by etherifying alkalized cellulose through an etherifying agent A and an etherifying agent B in sequence, the etherifying agent A is selected from water-soluble halogenated alkyl sulfonic acid and / or water-soluble halogenated alkyl sulfonate; the etherifying agent B is selected from water-soluble halogenated alkyl carboxylic acid and / or water-soluble halogenated alkyl carboxylate. According to the composite anionic cellulose ether, a sulfonic acid group and a carboxylic acid group are sequentially introduced, so that the composite anionic cellulose ether has relatively high temperature resistance and salt and calcium resistance; the compound can be used as a filtrate reducer for the drilling fluid, can effectively control the filter loss of the drilling fluid, and can improve the salt pollution resistance of the drilling fluid, especially the calcium and magnesium ion pollution resistance.

The invention discloses an ultra-deep well drilling wellbore pressure inversion correction method, and aims to improve pressure prediction precision and well control safety in an ultra-deep well drilling process. The method mainly comprises the following two parts: firstly, establishing a wellbore pressure calculation model, fully considering the change of drilling fluid density along with temperature and pressure based on a mass and momentum conservation equation in a drill rod and an annulus, performing discrete solution on the established control equation by adopting a finite difference method, and performing iterative calculation from a well bottom to a well mouth and from the well mouth to the well bottom, so as to obtain a well pressure calculation model; and acquiring pressure and physical property parameters of each node. Secondly, on the basis of model output, a friction correction factor is introduced, a nonlinear state space model is constructed, an unscented Kalman filter (UKF) algorithm is used for conducting dynamic estimation on the friction correction factor, and online self-adaptive correction on the wellbore pressure model is achieved; according to the method, the accuracy of wellbore pressure calculation is effectively improved, and reliable technical support is provided for ultra-deep well operation.

The invention relates to the field of geothermal well drilling, and discloses a gas lift reverse circulation well drilling method, which comprises the following steps of: determining formation pore pressure based on the height of a static water level in a well; setting the annulus bottom hole pressure to be equal to the formation pore pressure, and determining the reference dynamic water level height of the drilling fluid according to the annulus bottom hole pressure, the relevant parameters of the gas lift reverse circulation drilling equipment and the relevant parameters of the drilling fluid; based on the reference dynamic water level height, a first target dynamic water level height is determined, in the drilling process, the dynamic water level height of the drilling fluid is controlled to be the first target dynamic water level height, and the first target dynamic water level height is lower than the reference dynamic water level height. By controlling the dynamic water level height of the drilling fluid in the drilling process to be lower than the corresponding reference dynamic water level height when the annulus bottom hole pressure is equal to the formation pore pressure, the annulus bottom hole pressure can be controlled to be lower than the formation pore pressure, the drilling process is kept in an unbalanced state, the drilling fluid can be prevented from leaking into the formation, and the drilling efficiency is improved. The heat storage is damaged.

A natural gas hydrate in-situ drilling and drilling fluid treatment system, comprising an offshore control platform (16), a natural gas hydrate subsea in-situ drilling device, a disassembly and assembly servo system, a drilling fluid feeding system, a wellhead flowback drilling fluid treatment system, a hydrate decomposition gas treatment system, a wellhead flowback drilling fluid tailings treatment system, a buoyancy control system (15), and a main control electric-power communication support system (17) connected to each system and controlling same, wherein the natural gas hydrate subsea in-situ drilling device and the drilling fluid feeding system are separately detachably connected to the wellhead flowback drilling fluid treatment system; and the hydrate decomposition gas treatment system is separately connected to the wellhead flowback drilling fluid treatment system, the natural gas hydrate subsea in-situ drilling device and the drilling fluid feeding system. Using unattended automation technology realizes the operation of the natural gas hydrate in-situ drilling and drilling fluid treatment system, such that the production process is simplified, automation and modularization are achieved, and subsea in-situ drilling can be performed on a large scale, thus greatly reducing the operation costs.

Disclosed embodiments relate to a pulsed-power drilling system, in which a pulsed-power drill is conveyed downhole and operated via coiled tubing. The coiled tubing may be configured to simultaneously transmit power and drilling fluid downhole. For example, the coiled tubing may include a flexible hollow fluid tube configured to transport drilling fluid therein, and a flexible cable tube disposed within the fluid tube. The cable tube may have one or more cable disposed within protective tubing, protecting the cables from drilling fluid in the fluid tube. Methods of making and using such coiled tubing with pulsed-power drills are also disclosed.