1944 results about "Wellbore" patented technology

The invention relates to the technical field of oil and gas field development, and discloses an ultra-large type true triaxial hydraulic fracturing fracture evolution path prediction method and system.The prediction method comprises the steps that a coupling geomechanical model integrating microscopic, macroscopic and wellbore flow scales is constructed; initializing the model and performing crack initial expansion simulation; collecting construction data in real time, and dynamically optimizing model parameters through a data assimilation algorithm; performing fracture evolution advanced prediction by using the updated model; and generating an optimization decision based on the prediction result and feeding back to the construction site. According to the method, fusion of a multi-scale physical mechanism and real-time dynamic prediction is realized, and accurate prediction and active control can be performed on crack expansion under the ultra-large true triaxial condition.

The invention relates to a wellbore multiphase flow model numerical solution and gas-liquid distribution state inversion method and system, and belongs to the technical field of petroleum engineering, and the method comprises the steps: 1, constructing and training a physical information neural network for drilling wellbore multiphase flow dynamic simulation and overflow gas distribution state inversion; determining input and output of the physical information neural network; determining a loss function of the physical information neural network; training a physical information neural network; 2, designing an adaptive optimization algorithm, optimizing the final solution precision and convergence speed of the physical information neural network, and obtaining an adaptive physical information neural network; designing an adaptive activation function; designing a self-adaptive sampling mechanism based on residual errors; 3, based on the self-adaptive physical information neural network, numerical solution and gas-liquid distribution state inversion of the shaft multiphase flow model are achieved. According to the method, the problem that a traditional numerical method usually needs high-precision grid division and a large number of computing resources is effectively solved.

The invention relates to the technical field of petroleum and natural gas engineering, and discloses an oil and gas reservoir optimized mining method based on multi-modal data, which comprises the following steps: constructing an oil and gas reservoir multi-modal data acquisition system, seismic wave field data, logging interpretation data, production dynamic data, micro-seismic monitoring data, underground temperature and pressure time sequence data and shaft structure parameter data are obtained through the acquisition system; and performing space-time alignment processing on the acquired multi-modal data, establishing a unified geological coordinate system and a time reference, and eliminating data isomerism caused by different acquisition frequencies and spatial resolutions. A six-dimensional heterogeneous data acquisition system covering a seismic wave field, well logging interpretation, production dynamics, micro-seismic monitoring, an underground temperature and pressure time sequence and shaft structure parameters is constructed, so that the depiction precision of a reservoir porosity field, a permeability field, a saturation field and a pressure field is essentially improved.

The invention relates to the technical field of petroleum drilling engineering, and particularly discloses an analysis and prediction system based on petroleum drilling and production data, which realizes virtual reconstruction of a physical drilling system by constructing a digital mapping body, and adopts a multi-source sensor network to collect drill string vortex frequency and wellbore temperature field gradient data. Forming a time sequence feature set through time sequence alignment and fusion processing; performing differential transformation and modal decomposition on the feature set to extract transient response feature vectors and generate a risk distribution diagram; establishing a parameter-risk correlation model, and decoupling mechanical vibration and thermal stress interference by solving a physical equation to obtain a dynamic risk index; the risk indexes and the process parameters are mapped to a three-dimensional grid to construct a multi-dimensional feature space, a feature fusion grid is adopted to achieve information aggregation and reconstruction, and comprehensive risk assessment indexes are generated; a dynamic early warning threshold value is established according to the evaluation indexes, and drilling parameters are optimized in real time through closed-loop control.

The invention discloses a geothermal development oil shale and CO2 geological storage integrated method, which relates to the field of complex oil and gas reservoir development, and comprises the following steps: designing U-shaped well process parameters, enabling CO2 fluid to flow to a high-temperature geothermal reservoir through a descending section of a U-shaped well, injecting the CO2 fluid into the oil shale reservoir along an ascending section of a shaft after sufficient heat exchange, preheating the oil shale, and storing the CO2 fluid into a high-temperature geothermal reservoir through the descending section of the U-shaped well. Terrestrial heat extraction and utilization are realized; after the temperature of the oil shale layer rises to the target temperature, the oil shale layer is further heated through manual heating, and in-situ conversion development of the oil shale is achieved; after completion, produced CO2 is injected into the oil shale layer again through the U-shaped well, and collaborative development of CO2 geological storage, geothermal extraction and oil shale in-situ conversion is achieved. Geothermal energy is efficiently extracted through CO2 and used for oil shale in-situ pyrolysis, the extra manual heating cost needed by oil shale in-situ conversion is remarkably reduced, and the economic feasibility of a pure storage project and oil shale in-situ conversion development is improved.

This disclosure relates to a predictive lookahead system that generates simulated or predicted wellbore trajectory plans in a drilling environment and determines when a simulated wellbore trajectory plan is at risk based on various lookahead metrics, such as torque and drag (T&D) metrics and hydraulic pressure metrics. For instance, the predictive lookahead system uses a predictive framework with various steps to determine if drilling metrics for a predictive wellbore trajectory plan, such as T&D metrics and / or hydraulic pressure metrics corresponding to subsurface formations, may exceed one or more risk threshold limits and cause damage to the drill bit, drill string, casing, and / or surface rig. The predictive lookahead system determines whether a predictive wellbore trajectory, which aims to converge with a previously planned wellbore trajectory, can proceed safely along the projected trajectory without exceeding T&D, pressure window, or other lookahead metric limits in the wellbore.

The invention belongs to the technical field of petroleum and natural gas engineering, and particularly relates to a logging data intelligent inversion method fusing an attention mechanism and a convolutional neural network, and the method comprises the steps: S100, selecting a borehole which is subjected to well drilling and logging as a research well, and obtaining the drilling, logging and logging data of the research well; s200, constructing a unified depth reference of well drilling, well logging and well logging data, and improving the resolution of the well drilling and well logging data by adopting an interpolation method; s300, constructing an attention mechanism module based on a multi-scale adaptive compression excitation network, and improving the modeling capability through triple mechanisms of multi-scale feature perception, adaptive compression proportion adjustment and residual enhancement attention weight; s400, constructing a feature extraction and regression prediction network based on a one-dimensional convolutional neural network; s500, supervised learning training is carried out on the inversion model until comprehensive evaluation index requirements are met; and S600, intelligent prediction and inversion of the logging curve are carried out by using the trained model. According to the invention, intelligent and efficient inversion of the logging data by using the low-cost drilling and logging data is realized.

The invention discloses an intelligent diagnosis system for health and collapse risks of a vertical shaft structure, and relates to the technical field of mine safety monitoring. The acute lesion diagnosis module is used for diagnosing acute physical damage of a sensing optical fiber so as to generate a spatial data confidence index map; the chronic lesion compensation module is used for compensating chronic signal drift caused by internal residual stress relaxation of the sensing optical fiber so as to establish a dynamic zero correction vector; the signal fusion processing module purifies the original apparent strain information through a nonlinear weighting algorithm according to the output of the first two modules, and reconstructs a net structure strain field calibrated by the space-time drift of the instrument; and the collapse risk prediction module is used for intelligently diagnosing and predicting the structural health state and the collapse risk of the vertical shaft. According to the method, the authenticity of monitoring data can be improved from the source, the false alarm rate is greatly reduced, and long-term and weak structural evolution omen are effectively captured.

The application belongs to the technical field of oil well production management, and discloses a submersible electric pump well group management system and method based on digital twinning. The method collects the operation data of the submersible electric pump unit and the environmental data in the wellbore in real time, constructs a multi-scale digital twinning model for the received data, obtains the mechanical structure and electrical characteristics of the submersible electric pump unit, the multiphase flow dynamics in the wellbore, and the geological pressure field data, performs trend prediction on the multi-scale digital twinning model operation parameters, energy efficiency indicators and health status of each well, correlates the trend prediction data with the historical health database through a machine learning algorithm and an expert knowledge base, completes early warning and intelligent diagnosis of equipment failure, and generates a maintenance strategy. The application can assist managers in decision-making based on the historical health database. The application can realize unified management and intelligent well inspection of multiple well sites, and greatly improves the efficiency of oil well production management.

The invention provides a tight gas and deep coal bed gas collaborative exploitation simulation experiment device. The tight gas and deep coal bed gas collaborative exploitation simulation experiment device is composed of a shaft simulation device, a reservoir simulation device, a gas-liquid two-phase flow supply device and a control system. The casing pipe is provided with a plurality of transparent converging sections, and the oil pipe can be downwards inserted to different layers. And the gas-liquid two-phase flow supply device is provided with a plurality of groups of independent gas-liquid conveying manifolds which are respectively connected with each convergence section of the sleeve through the reservoir simulation device, so that the independent regulation and control of seepage parameters and production pressure difference of each layer are realized. The control system integrates pressure and flow acquisition and image recording functions, monitors and analyzes data in real time, is used for simulating an interlayer coupling relationship, a mutual interference mechanism and dynamic productivity response during multi-layer commingling production, and provides an experimental basis for collaborative production layer strategy optimization.

The invention discloses a rigid casing stabilizer and relates to the technical field of oil field low-carbon exploitation. An annular counter bore is upwards formed in the lower end face of the centralizing sleeve, a lifting sleeve is arranged in the annular counter bore and connected with the annular counter bore through threads, the upper portion of the lifting sleeve is connected with a compression spring A through a plane bearing, the upper portion of the compression spring A abuts against the bottom of the annular counter bore, and a balance cutting mechanism is arranged on the lower portion of the lifting sleeve. The drilling tool has the beneficial effects that the balance cutting mechanism is arranged on the lower portion of the centralizing sleeve, when the well diameter is irregular during casing running and the main cutting block and the auxiliary cutting block encounter the inner protrusion of the well wall, the lifting sleeve starts to rotate and ascend, the main cutting block and the auxiliary cutting block cut the well wall, the casing can be smoothly put into a shaft, and the drilling tool is convenient to use. And during cutting, large bending force cannot be formed on the casing pipe, so that the casing pipe is protected.

The invention belongs to the technical field of petroleum and natural gas exploration and development, and particularly relates to a coiled tubing bottom seal dragging pressure testing and leakage finding packer and a using method thereof, and the pressure testing and leakage finding packer comprises an upper centralizer, a pressure balancing mechanism, a setting packing mechanism and a lower centralizer which are coaxially and sequentially connected in a threaded mode. The pressure balance mechanism comprises a sleeve shell assembly and a pressure relief assembly. A pressure relief opening is formed in the side face of the sleeve shell assembly, and the pressure relief assembly is arranged in the sleeve shell assembly. The setting packing mechanism comprises a central pipe; a rubber sleeve assembly, a slip assembly and a centralizing assembly are sequentially installed on the basis of the center pipe from top to bottom, the rubber sleeve assembly is movably connected with the center pipe in an axial limiting mode, the slip assembly is fixedly connected with the centralizing assembly, and the centralizing assembly is movably connected with the center pipe based on the track pipe groove. According to the technical scheme, pressure bearing reasons and leakage point positions which cannot be found out by dragging pressure testing for multiple times in one-time well entering can be achieved, and it is guaranteed that follow-up fracturing construction operation of the shale gas well is safely and efficiently carried out.

The invention relates to a pour point depressing paraffin inhibitor and a preparation method thereof. The pour point depressing paraffin inhibitor is prepared from the following raw material components: graphene oxide, acrylic acid, a dispersing agent, a catalyst and a solvent, wherein the content of the graphene oxide is 4%-14.5% by mass, the content of the acrylic acid is 38%-76% by mass, the content of the dispersing agent is 4%-6% by mass, and the content of the catalyst is 1%-2% by mass. The graphene oxide is introduced into the pour-point depressing paraffin inhibitor provided by the invention, the size nanocrystallization is easy to prevent the formation of wax crystals in crude oil, the pour-point depressing effect is good, and the crude oil is conveniently exploited from a shaft and transported by a crude oil pipeline.

The invention relates to an ultra-deep well perforation test combined operation tubular column safety evaluation method. The method comprises the following steps that S1, a packer lower portion perforation detonation annulus pressure evolution finite element model and a dynamic negative pressure evolution numerical model after perforation detonation are established; s2, establishing a perforation instant tubular column coupling impact vibration evolution model, and determining main control factors; s3, establishing a dynamic evolution numerical model of the shock absorber at the moment of perforation, and obtaining a dynamic evolution model of the lower oil pipe of the packer, the shock absorber and the perforating gun at the moment of perforation; and S4, evaluating the safety of the pipe column at the lower part of the packer by taking the Mises yield criterion as an evaluation standard. The influence of perforation detonation transient wellbore pressure and dynamic negative pressure on a lower tubular column system of the packer is fully considered, the dynamic response rule of the tubular column is disclosed through numerical simulation and theoretical analysis, risk control measures are put forward, and the safety of the packer is improved. Theoretical basis and technical support are provided for optimal design of an ultra-deep well perforation test combined operation scheme and safety of an oil testing process.

The invention relates to the field of oil and gas reservoir drilling, and provides a borehole wall stability analysis method for a deepwater shallow long horizontal well, which comprises the following steps: carrying out mechanical parameter test on a weakly cemented rock sample to obtain basic mechanical characteristic parameters; performing time-varying strength modeling on the weak cementation constitutive structure to obtain a damage evolution model; performing three-dimensional finite element modeling on the stratum around the borehole to obtain a numerical calculation model; establishing a control equation set, and discretely solving the control equation set through the numerical calculation model to obtain a field variable solving result; and well wall stability analysis is carried out based on the field variable solving result, and an analysis result is obtained. According to the method, the well wall stability prediction precision of the deep-water shallow-layer long horizontal well is improved, and the safety of well drilling is improved.

Methods and systems are provided for drilling a secondary wellbore relative to a target wellbore, which involve drilling the secondary wellbore with a bottomhole assembly (BHA) that extends from a drill string. The BHA includes a magnetic field detector, a steering component, a drill bit, and at least one processor. The magnetic field detector is configured to detect a time- varying magnetic field generated from a rotating magnetic source of a drilling tool disposed in the target wellbore. The at least one processor is configured to i) use data output by the magnetic field detector to continually determine distance and direction or azimuth of the magnetic source relative to the BHA while drilling, and ii) use the distance and direction or azimuth of the magnetic source relative to the BHA while drilling to adjust the steering of the drilling performed by the BHA as controlled by the steering component of the BHA. The operations of the least one processor can be configured to adjust steering of the drilling of the BHA in order to maintain a set distance and direction or azimuth relative to the target wellbore, autonomously without surface input or interference, whilst drilling with the BHA.

The invention relates to the technical field of oil pipe leakage detection, in particular to an underground oil pipe leakage detection system, which comprises an underground permanent monitoring unit, which comprises at least one optical fiber sensor, and the optical fiber sensor clings to the outer wall of a production oil pipe or is integrated in an oil pipe coupling and extends along the depth of a whole shaft; the ground signal processing and analyzing unit is in communication connection with the underground permanent monitoring unit; wherein the optical fiber sensor is used as a distributed temperature sensor and a distributed sound wave vibration sensor at the same time, real-time on-line monitoring of oil pipe leakage is achieved, early warning can be given out at the initial stage of leakage, the accuracy of leakage recognition is improved through collaborative analysis of bimodal sensing data, the false alarm situation is effectively reduced, and the reliability of oil pipe leakage detection is improved. A distributed measurement mode provides meter-scale spatial resolution, the depth position of a leakage point is accurately positioned, normal production operation does not need to be interrupted during system operation, and the operation cost of an oil field is reduced.

The invention provides an underground centralizing device and method for a casing deformation well, and relates to the technical field of oil exploitation equipment, and the underground centralizing device comprises a coiled tubing, at least two sleeves, a connecting rod mechanism and a contact area increasing mechanism. A convex ring is arranged on the outer wall of the coiled tubing, the sleeve is slidably sleeved on the coiled tubing, and the convex ring is located in the sleeve to form a pressure cavity. The connecting rod mechanism is connected to the sleeve and used for expanding outwards when the sleeve moves relatively. The sleeves are close to each other by pressing the coiled tubing, and the connecting rod mechanism is driven to expand towards the well wall to achieve righting. The contact area increasing mechanism increases the contact area with the well wall through linkage cooperation of a gear, a rack and a top plate, and the connecting rod is prevented from sinking into the well wall. A mechanical connecting rod structure is adopted to replace a traditional air bag type centralizer, the influence of the gravity effect on the centralizing effect is effectively avoided, and it is ensured that the coiled tubing is accurately kept in the center position of a shaft.

The invention provides a heavy oil thermal-flow coupling development experimental device and method based on microwave-assisted gravity drainage, and belongs to the field of oil-gas field development. The experimental device comprises a three-dimensional oil reservoir simulation system, a microwave-assisted heating system, a horizontal well injection-production regulation and control system and a multi-field monitoring system; the microwave auxiliary heating system comprises a microwave generation regulation and control system, a microwave transmission system and a shaft integrated microwave radiator, the microwave generation regulation and control system comprises an industrial grade microwave generator, a power regulator and a PLC, and the microwave transmission system comprises a microwave coaxial cable and a microwave waveguide tube bundle; and the microwave generator is continuously connected with the microwave waveguide tube bundle and the shaft integrated microwave radiator. According to the heavy oil thermal-flow coupling development experimental device and method based on microwave-assisted gravity oil drainage, the technical problems that an existing deep heavy oil thermal recovery experimental device cannot reproduce a'thermal-flow-force 'multi-field coupling environment, the microwave heating adaptability is poor, and the experimental scale and the field deviation is large are solved. The heavy oil thermal-flow coupling development experimental device and method based on microwave-assisted gravity oil drainage solve the technical problems that an existing deep heavy oil thermal recovery experimental device cannot reproduce the'thermal-flow-force' multi-field coupling environment.

The invention discloses a deep sea ultra-shallow gas layer drilling shaft multiphase flow obstacle risk prediction method, and relates to the technical field of petroleum and natural gas engineering, and the method comprises the following steps: building a shaft-sedimentary layer heat-force-solid-chemical multi-physics field coupling model and a 3D model, setting initial boundary conditions, and dividing grids; model parameters are input, a finite element method is used for solving a multi-physics field coupling numerical value, and the gas invasion amount and the hydrate blocking rate are calculated; analyzing a gas invasion-migration-pressure evolution mode; researching the secondary generation and deposition characteristics of the hydrate; establishing a risk assessment system based on the parameters to divide risk levels; a historical data verification model is selected, and when the deviation rate exceeds 15%, parameters are optimized and solution is carried out again. According to the method, the defects of traditional single-field analysis are overcome, the multi-phase flow obstacle risk prediction accuracy is improved, intervention guidance is provided, model verification guarantees stability, safe and efficient mining of the deep sea ultra-shallow gas layer is assisted, and related development technology progress is promoted.

The invention discloses a rock unconventional reservoir carbon dioxide fracturing temperature field simulation method and system, and belongs to the technical field of oil and gas exploitation. Rock unconventional reservoir parameters and wellbore parameters are obtained, fluid physical property parameters of carbon dioxide fracturing fluid flowing in a wellbore are determined, and a multi-dimensional physical partition model is constructed; the unconventional reservoir is divided into a plurality of physical areas including a fluid flowing area, a static fluid area, a solid area and a porous medium area; thermal boundary conditions of all physical areas are coupled through an energy conservation equation, stratum elasticity modulus and Poisson's ratio are added to the thermal boundary conditions, a thermal-force coupling equation is constructed, carbon dioxide fracturing construction parameters obtained in real time are estimated, temperature field distribution nephograms of carbon dioxide fracturing fluid at different moments in the shaft flowing process are obtained, and the temperature field distribution nephograms of the carbon dioxide fracturing fluid at different moments are calculated. According to the method, the temperature distribution rule of different fracturing stages in the shaft-crack direction can be truly reflected.

A while-drilling acoustic auto-tracking wellbore tool and a method for using same. The tool comprises: a power generation and communication system (100), which comprises a power generation system and a communication system, wherein the communication system is used for bidirectional transfer of measurement data and a control instruction; a power and measurement and control system (200), which comprises a measurement while drilling system, wherein the measurement while drilling system is used for measuring inclination and azimuth data of a newly drilled borehole, and transmitting the data to the communication system; and an acoustic measurement and guidance system (300), which comprises an acoustic emission and measurement and control system, wherein the acoustic emission and measurement and control system is used for emitting an acoustic signal in the newly drilled borehole, receiving a return signal and transmitting the return signal to the communication system. The solution solves the difficult problems of communicating a newly drilled well and an old borehole, determining the distance between a drill bit and the old borehole in real time, etc. The acoustic emission and measurement and control system emits the acoustic signal in the newly drilled borehole, receives the return signal and transmits the return signal to the communication system, and the position of a wellbore is dynamically scanned and monitored in an acoustic while-drilling manner, thereby achieving the aim of performing measurement while drilling.

Systems and methods are disclosed herein for simultaneously milling an obstructions and collecting the resulting debris within a wellbore in an oil-and-gas setting. An example debris collection tool can include a motor, centrifugal pump, gear boxes, bailers, and a pass-through milling bit. A series of shafts can pass through the internal components of the tool and cause various components to rotate when driven by the motor. The gear boxes can lower the speed and increase the torque of rotating downhole components. The tool therefore can simultaneously drive the pump and milling bit at different speeds and torques. The centrifugal pump can include a flow control mechanism at allows the tool to control the flow of drilling fluid from the centrifugal pump into the surrounding subsurface.

The invention provides a shale reservoir hydraulic fracturing wellbore casing deformation risk judgment method which comprises the steps that geological parameters and principal stress of a target area are obtained, and the principal stress comprises horizontal principal stress, maximum principal stress and vertical principal stress. And determining an included angle between the fault plane and the hydraulic fracture plane according to the normal vector of the fault plane and the normal vector of the hydraulic fracture plane. And calculating by substituting the geological parameters, the principal stress and the included angle into an established stress calculation model of the fault plane to obtain shear stress and normal stress of the fault plane in the target area. And calculating by substituting the shear stress and the normal stress into the established displacement component calculation model to obtain the slip component of the fault plane in the target area. And performing safety early warning based on the risk level. The fault slip amount is calculated by accurately identifying the stratum physical property parameters and the fault structure, so that the casing deformation risk is judged.

The invention relates to the technical field of heavy oil reservoir exploitation, in particular to a device and a method for realizing viscosity-reducing huff-puff exploitation of heavy oil by injecting natural gas into a well and pressurizing. According to the technical scheme, a gas supply pipeline is tripped into an annular space between a sleeve and a pump cylinder, the upper end of the gas supply pipeline is connected with a natural gas injection device on the ground, and the lower end of the gas supply pipeline is communicated with a gas inlet of an underground natural gas booster pump; a gas injection packer is installed on the lower middle side of a pump cylinder, an oil inlet hole is formed in the pipe wall of the lower side of the gas injection packer, and the lower end of the gas injection packer is connected with an underground natural gas booster pump through a transition adapter. The device has the advantages that the pressure of natural gas can be increased in a relay mode, the natural gas is dynamically mixed and dissolved in thickened oil, the viscosity of the natural gas is remarkably reduced, the natural gas is increased along with volume expansion, flowing to a shaft is facilitated, in addition, the foam oil effect can be formed, and the functions of reducing viscosity and increasing yield of a thickened oil reservoir are achieved; and the total operation cost is lower than the steam thermal recovery cost, and the safety is also greatly improved.

The invention provides a hydraulic fracturing simulation device, which comprises a pressure pump, a function module, an execution module, a visual display module and a valve assembly, the function module comprises a sand mixing unit and an oil-water separation unit, the execution module comprises a shaft simulation unit and a multi-stage crack simulation unit, and the shaft simulation unit and the multi-stage crack simulation unit are communicated. A gradient pressure triggering structure is arranged in the multi-stage crack simulation unit so as to realize multi-stage crack progressive expansion; the valve assembly comprises a first valve, a second valve, a third valve and a fourth valve, the first valve is connected with the pressure pump and the sand mixing unit, the second valve is connected with the sand mixing unit and the shaft simulation unit, the third valve is connected with the pressure pump and the oil-water separation unit, and the fourth valve is connected with the oil-water separation unit and the shaft simulation unit; thus, through integrated design, a valve assembly double-loop switching mechanism and gradient triggering and visual collaborative layout, the requirements for integration, continuity, high simulation and high precision of the hydraulic fracturing experiment are met, and the hydraulic fracturing experiment system fully meets the requirements for industry core development.

A system may include a lower completion disposed in a main bore of a multilateral well in a position downhole from a junction of the multilateral well. The system may also include a fluid separator configured to receive formation fluid, which includes oil and water, flowing from the lower completion. The fluid separator may be configured to at least partially separate the formation fluid into formation oil and formation water. The fluid separator may also be configured to output the formation oil, via a separator oil outlet, to flow uphole, and output the formation water, via a separator water outlet, to flow toward a lateral bore of the multilateral well. Further, the system may include a water cut sensor disposed uphole from the fluid separator. The water cut sensor may be configured to measure the percentage of water in the formation oil.

Some implementations include a method which comprises determining a drilling efficiency of a drill bit at a first depth in a wellbore formed in a subsurface formation based, at least in part, on a bit wear level of the drill bit, determining a cutting force mechanical specific energy of the drill bit at the first depth, and determining a rock strength of the subsurface formation at the first depth based on the drilling efficiency and the cutting force mechanical specific energy of the drill bit.

A milling bit is disclosed for debris collection within a wellbore. A check valve can be part of a debris removal tool that includes a motor, a pump, a gearbox, a bailer, the milling bit, 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.

The invention relates to the technical field of oil and gas field development, in particular to an ultra-deep gas well production string multi-mode leakage simulation experiment device and method. According to the technical scheme, the outer side of a shaft temperature and pressure coupling simulation system is connected with a reservoir gas supply simulation system, the middle of the shaft temperature and pressure coupling simulation system is provided with a multi-mode leakage simulation assembly, the lower end of a production oil pipe is connected with a reservoir-shaft coupling connector, and the upper portion of one side of a layered sand filling seepage tank of the reservoir gas supply simulation system is connected with a confining pressure loading unit through a pipeline; the lower portion of the layered sand filling seepage tank is connected with a reservoir fluid supply unit, and the outlet end of the layered sand filling seepage tank is connected with a reservoir-shaft coupling connector through a pipeline. The experimental device has the beneficial effects that the experimental device for coupling the reservoir and the shaft is constructed, and the multi-mode leakage simulation assembly is adopted to realize body perforation leakage simulation and screw thread sealing failure simulation, so that the simulation of the ultra-deep gas well under complex working conditions is realized, and a scientific basis and a technical support are provided for leakage prevention and control of a production string of the ultra-deep gas well.