36 results about "Wellbore instability" patented technology

The invention belongs to the technical field of drilling fluid additives for petroleum drilling, and discloses a heat-resistant water-based drilling fluid additive as well as a preparation method and application thereof. The water-resistant water-based drilling fluid additive is a high-molecular compound which is formed by taking water as a solvent, dissolving animal bone glue to form a glue solution, and performing etherification reaction on the glue solution and bromoethane under the action of a chain transfer agent and a base catalyst. The preparation method comprises the following steps: adding animal bone glue into water, dissolving to obtain a glue solution, sequentially adding sodium hydroxide, sodium carbonate and bromoethane to form a reaction system solution, then adding a chain transfer agent, and heating and refluxing to react to obtain the water-resistant water-based drilling fluid additive. According to the prepared bromoethane modified bone glue, the chain transfer agent is added in the modification process, the technical defect that the molecular weight of the bone glue cannot be manually controlled is overcome, the inhibition effect is obvious, meanwhile, the rheological property of drilling fluid is not affected, and the problems of borehole wall instability and the like caused by shale hydration expansion in the drilling process can be effectively solved.

This invention relates to a drilling system and method for preventing wellbore instability during drilling through goaf areas, belonging to the field of drilling machinery technology. The objective is to provide a drilling system that effectively prevents wellbore instability during drilling through goaf areas. The technical solution includes a motor, a reducer, a clutch, a square drill pipe, a rotary table, a transmission rod, a drill pipe, a guide rod, and a drill bit. The motor is connected to the upper end of the square drill pipe via the clutch and reducer. The lower end of the square drill pipe passes through the rotary table and is connected to a first universal coupling. The first universal coupling is connected to the upper end of the transmission rod via a universal joint. The lower end of the transmission rod is connected to a second universal coupling via a cross bar. The lower end of the second universal coupling is connected to the upper end of the drill pipe via a flange. A rubber sheet is connected to the lower end of the drill pipe, and a solution damper is connected below the rubber sheet. The lower end of the solution damper is connected to the upper end of the guide rod, and the lower end of the guide rod is connected to the drill bit. This invention is used for drilling through goaf areas.

The invention relates to the technical field of geologic model analysis, in particular to a coal bed gas fracturing three-dimensional well network seam network design method based on a geologic model, and the method comprises the steps: firstly constructing a three-dimensional discrete geologic model containing grid node mechanical parameters, and generating a three-dimensional dynamic induced stress potential energy tensor field; performing low-potential-energy gradient optimization calculation by using the field to obtain a shaft space topological coordinate avoiding a high-potential-energy area so as to reduce the well wall instability risk; meanwhile, fracture extension simulation is cut off through an equipotential surface threshold value in the field, and hydraulic fracture geometrical morphology parameters matched with formation energy constraint are accurately determined; and finally, integrating the parameters to generate an optimized three-dimensional well pattern seam network design scheme, and realizing efficient and safe fracturing design based on the rock mass accumulated deformation energy distribution characteristics.

This invention provides a method for preparing a polyamine that combines inhibition and solid-phase cleaning effects. Compared with existing technologies, the polyamine prepared by this invention exhibits better inhibitory and solid-phase cleaning effects under high-temperature conditions, and also demonstrates better compatibility in drilling fluids. Its application in drilling fluids can effectively solve the wellbore instability problem in highly water-sensitive shale formations, and effectively avoid drilling fluid slurry formation problems caused by drill cuttings hydration, thus ensuring wellbore stability and drilling fluid cleanliness.

This invention belongs to the field of natural gas extraction technology in deep thin coal and rock formations. It discloses a directional anti-sticking drill string assembly and drilling method for horizontal wells in deep thin coal and rock formations. A closed-loop control system is formed between the drill bit trajectory control mechanism and the wellbore dressing and anti-sticking mechanism, encompassing near-bit high-precision sensing, real-time data transmission while drilling, surface analysis feedback control, active downhole directional correction, and synchronous wellbore dressing and protection. Multi-directional gamma sensors positioned near the drill bit provide high-resolution formation information; the bend structure of the downhole power drill string provides the direction of the wellbore trajectory; the non-magnetic bearing section ensures the stability of measurement while drilling and the reliability of communication; the surface control unit enables real-time decision-making and trajectory correction; and the wellbore dressing and anti-sticking mechanism simultaneously improves wellbore stability and cuttings carrying capacity. This significantly enhances the drilling throughput and resistance to coal seam collapse in complex sections of thin coal and rock formations while ensuring trajectory controllability, reducing the risk of sticking due to wellbore instability and cuttings accumulation.

This invention discloses an inhibitory water-based foam drilling fluid system to solve the wellbore instability problem currently existing in foam drilling. The system comprises 0.5%-1.0% fluorocarbon foaming agent, 0.2%-1.0% inhibitor, 0.04%-0.2% foam stabilizer, 0.2%-0.4% thickener, 1.0%-5.0% bentonite, and water as the balance. The fluorocarbon surfactant is a fluorocarbon surfactant containing a quaternary ammonium salt cationic structure, the inhibitor is a small-molecule amine salt structure inhibitor, and the large-molecule foam stabilizer is one or more combinations of starch, cellulose, and polyacrylamide. The foaming agent provided by this invention, when applied in foam drilling, possesses both strong foaming and inhibitory properties.

Aspects of the disclosure provide a method of mitigating liquid instability in controlled intra-well cross-flow between two, or more, zones accessed by a well. One or more embodiments define new functionalities necessary for dynamic multiphase flow (MPF) simulation to model, mitigate and control liquid instability observed in a well.

The present invention relates to a method for evaluating the aqueous expansion performance of an ultra-high temperature resistant expanded graphite plugging agent, and belongs to the technical field of drilling fluid treatment agents. The present invention provides a method for evaluating the aqueous expansion performance of an ultra-high temperature resistant expanded graphite plugging agent. The method first obtains a high-definition distribution map of expanded graphite in an aqueous phase using an optical microscope, then performs image processing on the map using Image J software and performs data analysis on the map using Origin drawing software, thereby obtaining thermal expansion data of the expanded graphite in an aqueous phase. Based on the 1 / 3 bridging rule, the 2 / 3 bridging rule, and target layer fracture information, an accurate mesh size specification suitable for the formation is given, thereby improving the matching degree between the plugging material and the formation fracture, reducing drilling fluid leakage, and reducing the risk of wellbore instability during the drilling process. In addition, the method is closer to the actual construction process, and the measurement results have stronger guiding significance for actual engineering applications.

The present invention belongs to the field of oil and gas development and discloses a method for predicting the failure conditions of weak planes in anisotropic reservoir bedding. The method comprises: determining the total stress component of the anisotropic reservoir circumferential well based on the anisotropic reservoir circumferential stress component caused by far-field stress and the anisotropic reservoir circumferential stress component caused by drilling, wherein the anisotropic reservoir circumferential stress component caused by drilling is determined by constructing constitutive equations, equilibrium equations, coordinated strain equations, strain-displacement relationships, and boundary conditions; determining the stress component around the perforation hole based on the effect of cementing on the radial stress transmission at the bottom hole and the total stress component around the anisotropic reservoir circumferential well; and determining the critical pressure for failure of the weak planes in the anisotropic reservoir bedding based on the Jaeger weak plane failure criterion and the stress component around the perforation hole. The present invention can provide theoretical support for the safety of oil and gas development operations in anisotropic reservoirs and effectively reduce the risk of wellbore instability.

The invention discloses a geomechanical method for quantitatively evaluating the well wall stability of a fractured formation, which comprises the following steps of: acquiring a crustal stress state, a rock strength parameter, a fracture occurrence and a fracture strength parameter according to seismic data, logging data and rock mechanics experimental data; according to the obtained parameters, determining the stress state of the complete rock of the target layer section and the instability index of the crack-containing rock; the instability index of the complete rock and the instability index of the crack-containing rock are solved through the stress state; the weight values of the parameters are considered, and a comprehensive instability index of the target layer section is obtained; and finally, according to the corresponding relationship between the calculated comprehensive borehole wall instability index and the instability degree, determining the borehole wall instability degree of the target interval corresponding to the instability index. According to the method, the crustal stress state, the rock strength parameter, the fracture occurrence and the fracture strength parameter are comprehensively quantified, comprehensive evaluation of the instability index is formed, and the objectivity and the accuracy of the evaluation result are improved.

The invention provides a CaCO3 / polymer-based plugging agent, a preparation method thereof and a water-based drilling fluid, the preparation method of the CaCO3 / polymer-based plugging agent comprises the following steps: S1, synthesizing CaCO3 in the presence of a modifier to obtain modified CaCO3; s2, taking the modified CaCO3 and a functional monomer as raw materials, adding a cross-linking agent, an initiator and a dispersing agent, and synthesizing a CaCO3 / polymer-based plugging agent by adopting a reversed-phase suspension polymerization method; wherein the functional monomers are styrene, acrylamide and N-vinyl pyrrolidone. The water-based drilling fluid based on the CaCO3 / polymer-based plugging agent is low in cost, has a good plugging effect, has temperature resistance and pressure bearing performance, and can solve the problem of well wall instability of a high-temperature well section.

The present disclosure provides a wellbore instability analysis method based on big data, which relates to the field of wellbore instability. The wellbore instability prediction based on big data analysis and deep learning, combined with existing wellbore instability theory and experimental research results, finds the main control factors and related factors of wellbore instability in the studied block. Based on data classification, a big data model is established to improve the accuracy of analysis and prediction through big data learning. Through the application of the big data model, the deep learning technology is used for regional wellbore instability evaluation and research, and finally the regional wellbore instability evaluation and prevention technology based on big data is formed. The wellbore instability analysis tool based on big data analysis mainly provides the safety density window for preventing wellbore instability, the control analysis of hole diameter change, the optimization of drilling fluid performance and additive dosage, adjacent well data analysis, ECD analysis and drilling time effect analysis through data analysis, so as to reduce the hydration swelling effect of the target formation rock and prevent wellbore instability. The present disclosure is suitable for wellbore instability prediction.

The utility model discloses an asymmetric three-petal arc-shaped rib wing screw centralizer which comprises a centralizer screw body, the two ends of the centralizer screw body are provided with connectors, a first arc-shaped rib wing is fixedly arranged on the periphery of the middle of the centralizer screw body, and a second arc-shaped rib wing is fixedly arranged on the periphery of the middle of the centralizer screw body. A second arc-shaped rib wing and a third arc-shaped rib wing are fixedly arranged on the periphery of the middle part of the centralizer screw rod body between 90 degrees and 120 degrees relative to the left side part and the right side part of the first arc-shaped rib wing respectively; by arranging the first arc-shaped rib wing, the second arc-shaped rib wing and the third arc-shaped rib wing and adopting asymmetrical layout structures with different sizes, the asymmetrical three-petal arc-shaped rib wing screw centralizer solves or relieves well wall instability and collapse caused by complex geological reasons in the drilling process of a coal seam well section; and therefore, the problems of difficulty in pulling out of the drill, difficulty in circulation and easiness in jamming of the drill are solved.

The present invention discloses a method for evaluating the risk of wellbore instability in different time domains of a porous saturated elastic medium. Geological mechanical parameters (including in-situ stress, pore pressure, and rock mechanical and strength parameters) of the target reservoir are obtained from logging data, and the uncertainty characteristics of the geological mechanical parameters are analyzed by combining mathematical statistics methods. Based on the stress solutions of the rock around the well in the instantaneous, short-term, and long-term conditions in a saturated porous elastic medium formation, the analytical solutions of the collapse pressure and fracture pressure of a vertical well in corresponding different time domains are derived. Depending on whether the probability distribution of the geological mechanical parameters can be obtained, the Monte-Carlo method or the first-order second-moment method is respectively used to quantify the uncertainty of the wellbore collapse pressure and fracture pressure. This method can more objectively quantify the influence of the uncertainty of the geological mechanical parameters on the wellbore collapse pressure and fracture pressure in a porous elastic medium formation under instantaneous, short-term, and long-term conditions, providing a theoretical support for preventing wellbore instability.

The invention belongs to the technical field of petrochemical engineering, and provides a deepwater superficial portion hydrate-containing stratum borehole stabilizer and a preparation method and application thereof. The deepwater superficial portion hydrate-containing stratum borehole stabilizer comprises a copolymer of a vinyl lactam monomer, acryloyl dopamine and a derivative of the acryloyl dopamine; the preparation method comprises the following steps: dissolving dopamine and a derivative thereof in a solvent, adjusting to be alkaline, adding an acrylic acid derivative with an acrylic acid or methacrylic acid group, reacting, dissolving the obtained acryloyl dopamine in a solution, mixing and dissolving with a vinyl lactam monomer and an initiator, and carrying out copolymerization reaction. After being added into a drilling fluid, the deepwater shallow hydrate-containing formation well wall stabilizer disclosed by the invention can play a multi-functional role, not only can improve the cementing property between hydrates and mineral particles and between mineral particles in a formation and improve the pressure-bearing strength of the formation, but also can inhibit the decomposition of the hydrates in the formation and the reduction of the strength of the formation, so that the drilling fluid can be well protected. And the well wall instability risk is reduced.

The present invention discloses a method for evaluating the risk of wellbore instability by using Nataf transformation to realize parameter correlation. First, the geomechanical parameter curve of the target reservoir is obtained based on well logging data and indoor core experiments, and the reservoir with the same lithology is used as the parameter sample data at the depth. In addition, considering the non-normal correlation problem existing in the parameters themselves, the K-S test and Pearson linear correlation coefficient are first used to establish the goodness-of-fit of the characteristic distribution function within the parameters and the correlation between the parameters; then the Monte-Carlo method and the Nataf transformation method are effectively combined to statistically calculate the wellbore instability pressure under the linear elastic theory. Finally, a quantitative evaluation of the wellbore instability risk of a directional well is achieved. This method can more objectively consider the true correlation between geomechanical parameters, improve the efficiency of simulation analysis, and realize the risk evaluation of wellbore collapse and rupture of any well, providing theoretical support for pre-drilling prediction and wellbore instability.

The present invention relates to the technical field of petroleum drilling. Disclosed are a plugging agent, and an oil-based drilling fluid and a use thereof. The plugging agent provided by the present invention has a multi-scale broad-spectrum strong plugging effect on formation micro-fractures, and the addition of the plugging agent into the oil-based drilling fluid can effectively solve the problem of wellbore instability and improve the safety of deep oil and gas exploration.

The present invention belongs to the field of geotechnical engineering and discloses a device and method for studying wellbore instability and gas leakage during hydrate extraction. The device includes a reactor system, a well system, a hydrate generation system, a hydrate extraction system, and a monitoring system. The device realizes real-time monitoring of wellbore instability and gas leakage during hydrate extraction. Compared with traditional research devices, the fluid-solid coupling process during extraction is considered, that is, under the action of hydrate phase change and sediment, the deformation of the sediment reservoir causes squeezing and shear damage to the wellbore and cement sheath, resulting in gas escape and leakage along the deformed wellbore, which will cause peeling of the cement sheath and corrosion of the wellbore, accelerate the instability of the wellbore and cement sheath, and further hinder gas and water production. The device has certain guiding significance for studying the fluid-solid coupling effect of sediments and wellbore in the hydrate extraction process under laboratory conditions.

The invention provides a rock debris image data processing method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring rock debris image data and carrying out image segmentation processing to obtain rock debris classification data and a mask pattern; calculating the mask pattern to obtain rock debris particle size distribution data; performing shape analysis processing according to the rock debris particle size distribution data to obtain rock debris shape characteristic data; performing rock debris contour calculation on the mask pattern to obtain shape category data; performing visualization processing on the rock debris particle size distribution data to obtain a rock debris particle size distribution diagram, and performing rock debris particle block length ratio distribution diagram on the rock debris shape characteristic data; and performing visualization on the shape category data of the rock debris particle blocks to judge the instability condition of the well wall of the current drilling well. The efficiency and objectivity of rock debris classification and particle size calculation are remarkably improved through automatic images; comprehensive quantification of physical attributes of the rock debris is realized based on particle size and shape conjoint analysis, one-sidedness of a traditional method is avoided, and analysis precision and classification accuracy are effectively improved.

This invention relates to the field of drilling fluid treatment agents, and discloses a formulation with reduced filtration loss properties, its preparation method, and its application. The method includes: (1) mixing an organic solvent, an oil-phase matrix material, and an organic hydrophilic modifier to carry out a first modification reaction, wherein the oil-phase matrix material is selected from asphalt and / or resin; (2) adding graphene material to the system obtained in step (1) to carry out a second modification reaction. The formulation prepared by this method can not only quickly form an oil film on the wellbore to seal cracks, but can also be widely used in well sections prone to wellbore instability at 60-120℃, while also effectively improving the lubrication performance of drilling fluids.

The invention relates to the technical field of oil reservoir engineering, in particular to a stratum well wall stability evaluation method and device based on a mineral logging technology, and the method comprises the steps that the volume content of water-sensitive minerals in a stratum mudstone sample to be evaluated is obtained; determining the water absorption rate of each water-sensitive mineral; according to the volume content and the water absorption rate of the water-sensitive mineral, calculating to obtain the plastic water-sensitive strength of the mudstone mineral; and evaluating the formation well wall stability based on the mudstone mineral plasticity water sensitivity. On the basis of the mineral water sensitivity mechanism, the X diffraction mineral logging technology is combined with the well logging diameter curve, the water-sensitive stratum well wall instability level standard is established, the well logging diameter is used for verification, the reliability is high, and the method has the advantages of being capable of obtaining data while drilling in time, high in efficiency and high in field applicability and is suitable for shale and well drilling. And the method can also be expanded to other water-sensitive compact sand shale stratums, and is wide in application range.

The invention relates to the technical field of oil exploration, and discloses a casing liquid column pressure automatic balancing device which comprises an upper connector, a lower connector and a pressure balancing device. The outer sleeve is arranged outside the upper joint; the first shear pin is arranged on the inner side of the upper connector. When the whole device is tripped into a well, the internal and external pressure difference can be balanced, so that the whole device can be prevented from being extruded and damaged by the liquid column pressure difference generated due to untimely grouting, the labor intensity of workers can be reduced, a large amount of energy consumption for casing running pump starting grouting is saved, and the problem that the grouting pipeline is not firmly fixed and cannot be damaged is solved. And manual grouting at a well mouth is not needed, the potential safety hazard in the grouting process is reduced, the casing running speed is improved by more than 30%, the time is saved, the time efficiency is improved, air is prevented from being pressed into a well in the grouting process, and the well wall instability and well control risk caused by the pressure of a liquid column in the well are reduced.

The present application belongs to the technical field of oil and gas drilling engineering, and particularly relates to a polymer-coated inhibitor for strong inhibition drilling fluid and a preparation method thereof; the inhibitor is prepared by aqueous solution polymerization of acrylamide, acrylamidomethylpropane sulfonic acid, dimethyldiallylammonium chloride, vinyltrimethoxysilane and two novel inorganic modified compounds. The two inorganic modified compounds are a titanate intercalated magnesium aluminum tin silicate nanocomposite and a polyoxometalate grafted rare earth doped cerium dioxide nanorod, respectively. The former is prepared by coprecipitation and intercalation reaction, and the latter is prepared by hydrothermal synthesis and graft modification. The present application significantly improves the hydration inhibition capacity for shale, and can still maintain stable coating effect in high temperature and high salt environment, effectively solving the problem of wellbore instability. The preparation method is simple in process, the raw materials are all commercially available, and is suitable for industrial production, and has a broad application prospect in the field of water-based drilling fluid.

The invention discloses a fractured stratum modeling method for establishing a cluster template through three-dimensional scanning, which comprises the following steps: step 1, generating a real rock contour through three-dimensional scanning of a real rock sample, and establishing a basic flexible cluster template; 2, establishing a discrete element parameter calibration model, and simulating to obtain various mechanical parameters of the rock sample; step 3, establishing a real fractured stratum model; and 4, extracting a crack network structure by utilizing the well wall instability model in discrete element simulation, and further controlling the well wall instability phenomenon influenced by the well wall. According to the method, the contour of the rock block is obtained through three-dimensional scanning, the stratum model is constructed through the basic principle of the discrete element method, the cementation characteristic of the rock is restored, fracture of the rock block is simulated through Cluster, the particle crushing effect is reflected, namely, a more accurate crushed stratum well wall model is established, and the model is applied to the field of well wall construction. And the evaluation of the instability characteristics under the conditions of different fractured stratums, different fracture development degrees and the like can be realized.

The invention discloses a borehole wall stability analysis and risk evaluation method based on a quasi Monte Carlo method, and relates to the technical field of petroleum and natural gas drilling, and the method comprises the following steps: carrying out data cleaning and preprocessing on multi-source parameters, and carrying out parameter distribution modeling to obtain a multi-parameter joint probability distribution model; a quasi-Monte Carlo sampling method is utilized to obtain large-scale parameter combination samples with uniform sample coverage, and well wall stress, collapse conditions and fracture conditions are calculated to obtain collapse coefficients and fracture coefficients under each sample; performing variance decomposition according to a corresponding relation between each input parameter and a borehole wall instability result, identifying key control factors, constructing a training sample set, and training the long-short-term memory neural network model; and inputting related parameters obtained in an actual drilling process into the trained long-short-term memory neural network model to obtain a borehole wall stability result. By implementing the method provided by the invention, the accuracy and reliability of borehole wall stability analysis and risk prediction can be improved.

Aspects of the disclosure provide a method of mitigating liquid instability in controlled intra-well cross-flow between two, or more, zones accessed by a well. One or more embodiments define new functionalities necessary for dynamic multiphase flow (MPF) simulation to model, mitigate and control liquid instability observed in a well.

The present application relates to the technical field of oil reservoir engineering, and is a formation borehole wall stability evaluation method and device based on mineral logging technology, which comprises the following steps: obtaining the volume content of water-sensitive minerals in a mudstone sample of a formation to be evaluated; determining the water absorption rate of each water-sensitive mineral; calculating the plastic water-sensitive strength of the mudstone mineral based on the volume content and water absorption rate of the water-sensitive mineral; and evaluating the formation borehole wall stability based on the plastic water-sensitive strength of the mudstone mineral. The present application is based on the water sensitivity mechanism of minerals, combines X-ray diffraction mineral logging technology with well diameter curves, establishes a wellbore instability grade standard for water-sensitive formations, and is verified by well diameter logging, which is highly reliable, has the characteristics of timely and efficient data acquisition while drilling, and is highly applicable in the field. The present application is not only suitable for mud shale, but also can be extended to other water-sensitive tight sand-shale formations, and has a wide application range.

The invention discloses a borehole wall collapse pressure analysis method and device based on mudstone hydration. Comprising the steps that a mudstone well wall is regarded as a semi-permeable membrane, chemical potential difference is introduced, and a drilling fluid invasion physical model and a multi-field coupling equation under the drilling fluid invasion mudstone multi-field coupling condition are established under the solute diffusion condition; based on the assumed condition of drilling fluid invading mudstone, a well circumference stress calculation model under the multi-field coupling condition and a hydration mechanical stress balance equation, obtaining an all-directional stress expression under the hydration effect and boundary conditions of well wall instability calculation of the drilling fluid invading physical model, and obtaining stratum well circumference stress under the hydration effect; the change rule of rock mechanical parameters along with the formation water content is analyzed, a borehole wall collapse pressure model after mudstone hydration is established based on linear elastic hypothesis of the mudstone borehole wall and superposition of formation well circumferential stress, and the well circumferential borehole wall collapse pressure after mudstone hydration is solved in combination with actual drilling data. The method can be used for reasonably predicting the borehole wall collapse pressure of a mudstone-containing interlayer or sand mudstone.

The invention discloses a method for calculating the well wall falling block stacking height in the open hole well production process. The method comprises the steps that a reservoir rock mechanics parameter profile and a reservoir geomechanics parameter profile are calculated through a rock core mechanics experiment and field data; a true triaxial well wall instability experiment is carried out, well wall falling blocks are collected, and the natural stacking density of the well wall falling blocks is calculated; simulating a well wall instability process by a numerical simulation method, and drawing a well wall instability range chart; performing two-dimensional interpolation on the well wall instability range chart to obtain the well wall instability range of the whole well section of the open hole well, and calculating the total mass of well wall falling blocks through integration; and calculating the natural accumulation height of the falling blocks on the well wall. According to the method, the collapse instability range and the falling block stacking height under different production pressure differences can be calculated, and a theoretical basis is provided for design of the production pressure differences in different production stages.