Abstract: The present invention relates to a multi-capillary force curve averaging method based on the overall virtual measurement of a plurality of samples. The method includes the following steps: 1, taking m types of rock samples, obtaining a capillary force-saturation curve, an apparent volume and a porosity of each sample; 2, inspecting the quality of the capillary force-saturation curve of each sample and preprocessing the end points of each curve; 3, calculating an averaged wet phase saturation corresponding to different capillary force values of the plurality of samples under the overall virtual measurement of a plurality of samples; and 4, denoting data points on a graph by using the wet phase saturation as the abscissa and capillary force as the ordinate, and finally connecting all data points smoothly to obtain the averaged capillary force curve.

Abstract: The present invention discloses a three-dimensional in-situ characterization method for heterogeneity in generating and reserving performances of shale. The method includes the following steps: establishing a logging in-situ interpretation model of generating and reserving parameters based on lithofacies-lithofacies-well coupling, and completing single-well interpretation; establishing a 3D seismic in-situ interpretation model of generating and reserving parameters by using well-seismic coupling; establishing a spatial in-situ framework of a layer group based on lithofacies-well-seismic coupling, and establishing a spatial distribution trend framework of small layers of a shale formation by using 3D visualized comparison of a vertical well; and implementing 3D in-situ accurate characterization of shale generating and reserving performance parameters by using lithofacies-well-seismic coupling based on the establishment of the seismic-lithofacies dual-control parameter field.

Abstract: A drill string rotation controller includes an anti-torque balance module, a TC bearing retaining ring, an upper TC bearing, an upper thrust ball bearing, an upper Haval ring, a middle seal retaining ring, an upper mandrel, an upper shell, a rotary control cylinder, an upper spring, a spline shell, a spline sleeve, a spline mandrel, a lower shell, a spring push sleeve, a lower spring, a floating piston, a lower mandrel, a bulkhead, a lower thrust ball bearing, a lower Haval ring, a lower TC bearing, a conversion joint, an anti-drop joint, a lower joint, and a control pin. The rotary control cylinder causes the spline sleeve to switch the transmission relationship between the spline mandrel and shell. Therefore, the drill string rotation controller controls the conversion between the composite drilling mode and the directional drilling mode.

Abstract: An oil and gas fracturing tool is disclosed, mainly involving a fracking tool with an electromagnetic intelligent control sliding sleeve including an outer sleeve section, a dart body section and a control section. The outer sleeve section is at the target location to be fractured. The effect of fracturing is mainly achieved by the dart body, which has an activated state and an inactive state. The initial state is inactive, and the front locking tip can be deformed under pressure during displacement. The diameter can change to pass through any sliding sleeve. When the dart body is counted and is about to reach the fracturing position, the front locking tip is blocked from deformation and cannot be reduced in diameter, thus pressurizing to control the fracturing effect. The control part includes a sensor module, a drive module, a main control module and a power supply module.

Abstract: A spiral magnetic fluid composite sealing structure of a roller bit comprising a cone leg and a roller, wherein the roller and the cone leg are in rotatable connection in a fitting manner through a roller inner hole and a cone leg shaft journal, a sealing groove is formed in an opening end of the roller inner hole, and a spiral magnetic fluid sealing assembly is arranged in the sealing groove. Through the arrangement of the spiral magnetic fluid sealing assembly, a spiral sand discharging effect is realized, compared with a passive sealing mode, the sealing performance is greatly improved by active sand discharging mode, and the service life of sealing is significantly prolonged; a slurry sealing effect of magnetic fluid seals is realized, resulting the sealing gap is tightly sealed under the magnetic action; in addition, the automatic compensation function of magnetic fluid can also be realized.

Abstract: The present invention discloses an evaluation method for acid fracturing effect based on the theory of acid-frac “stimulated zone”, comprising the following steps: establish a structured reservoir grid, and add initial artificial fractures to the structured reservoir grid; establish a fracture propagation model considering the acid-frac stimulated zone, on the basis of the structured reservoir grid, conduct numerical simulation according to the fracture propagation model, and work out the seepage parameters during acid fracturing; establish a gas well production model, and calculate the pore distribution and liquid saturation distribution of the reservoir in gas well production; calculate the cumulative production of the gas well, and calculate the multiple proportion of cumulative production increase of the construction plan according to the cumulative production of the gas well; the greater the multiple proportion, the better the acid fracturing effect.

Abstract: The present disclosure discloses a method for calculating a safe drilling fluid density in a fractured formation, including the following steps: S1, performing image processing to identify a downhole fracture; S2, establishing three-dimensional (3D) geological models based on parameters of the downhole fracture, and establishing a drilling wellbore model based on a size and length of a wellbore; S3, assigning the model with material parameters, boundary conditions, and upper and lower bounds of an initial drilling fluid density, and calculating accuracy; S4, solving the 3D geological models using a 3-dimension distinct element code (3DEC) and determining stability of a well wall; S5, determining upper and lower bounds of a drilling fluid density using dichotomy; S6, repeating steps S4 to S5; and S7, after set accuracy conditions are reached, saving and outputting the safe drilling fluid density.

Abstract: A soluble metal sealing ring with a controllable dissolution rate and preparation process thereof include an aluminum alloy sealing ring matrix and a composite coating coated on an outer surface of the aluminum alloy sealing ring matrix whose standard electrode potential is greater than ?0.3 volts (V). The preparation process includes: (1) preparing a high-plastic aluminum alloy; (2) preparing the aluminum alloy sealing ring matrix by machining; (3) annealing the aluminum alloy sealing ring matrix; (4) mixing raw materials of the composite coating evenly; (5) preparing the composite coating on an outer surface of the aluminum alloy sealing ring matrix; (6) preparing holes. The soluble metal sealing ring solves problem that good sealing performance and good dissolving performance are difficult to obtain simultaneously in the existing product, and has advantages of good sealing performance, controllable dissolving rate, no blockage and others.

Abstract: The invention discloses an experimental system and a method for wellbore pressure testing under the coexistence of gas-kick and loss-circulation, comprising a drill string simulator, a wellbore simulator and a complex stratigraphic structure simulator communicated in sequence from top to bottom; further comprising a medium return pipeline for collecting the returning test liquid and a medium leakage module for collecting the leaking test liquid; further comprising a data acquisition system for collecting data during testing. In the present invention, the experimental system has a simple structure, and the experimental method can comprehensively cover the three stages of circulating, well shut-in and well killing during the occurrence of coexistence of gas-kick and loss-circulation, multiple groups of experiments can be conducted by changing a single variable at the same stage, thus making the experimental test results applicable to all stages of wellbore pressure control in drilling operation.

Abstract: A Hydrophilic-Lipophilic Deviation theory-based method is provided to prepare representative degassed oil with equivalent minimum miscible pressure to live oil. The method can reduce the number of trial and error type experiments during the representative degassed oil preparation process by measuring the MMP and EACN for dead and live oil. The representative degassed oil formulation could be easily predicted after determining the required MMP and EACN values. The prepared oil can reflect the key mechanism of multiple contact miscible mechanism in the process of gas flooding more accurately. It allows experiments that are inconvenient to use live oil to consider the mechanism of multiple contact miscibility easily.

Abstract: A double-chamber microcapsule includes a capsule core and a microcapsule wall encapsulating the capsule core, wherein the microcapsule wall is a thermo-sensitive polymer encapsulating the content of a second chamber; the capsule core is a pH responsive polymer encapsulating the content of a first chamber, the pH responsive polymer is obtained by polymerizing a pH responsive monomer and a cross-linking monomer; the content of the first chamber is different from the content of the second chamber, each is selected from a solid acid or a solid alkali.

Abstract: A negative pressure shale shaker integrated with negative pressure generation and gas-liquid separation includes a base, a liquid inlet buffer tank, a screen frame assembly, a support frame, a vacuum hose, a damping spring, a screen frame inclination angle adjustment device, a drainage hose, a negative pressure automatic drainage device, a vacuum pan, a three-way pipe, a liquid mist separator, a connecting pipe, a vacuum pressure limiting valve, a silencer and a negative pressure fan. A drilling fluid containing cuttings, after entering the screen with a negative pressure thereunder, rapidly passes through the screen along with air into a vacuum chamber. The air in the vacuum chamber is directly drawn away through holes formed on the side plates of the screen frame by the negative pressure fan.

Abstract: The present disclosure relates to a calculation method for predicting a proppant embedding depth based on a shale softening effect, including determining a spontaneous imbibition depth-soaking time curve; determining a Young’s modulus-soaking time curve of core surfaces; establishing a proppant embedding model containing a softened layer by a finite element method; conducting a numerical simulation to obtain an embedding volume-soaking time curve; and obtaining a calculation formula for a proppant embedding volume considering a softening effect.

Abstract: Disclosed are an instant dissolving device by mass transfer and stretching with a cleaning structure and a dissolving method thereof. The dissolving device consists of a liquid inlet, a stretching repetition unit and a mass transfer unit, the stretching unit is sequentially composed of an upper fixed fluted disc, a movable fluted disc and a lower fixed fluted disc all with a plurality of through holes, and the upper fixed fluted disc and the lower fixed fluted disc are fixed to the dissolving device housing; the polymer gel solution is formed into a “uniform” solution after passing through the mass transfer unit. The dissolving device in the present invention is easy to install, and achieves instant dissolution of the polymers and improves the dissolution efficiency through the joint action of forced stretching and mass transfer by high gravity.

Abstract: An intelligent maintenance and repair robot for small diameter and small flow oil and gas pipelines, including a frame, a speed control mechanism, a braking mechanism, an anchoring mechanism, and a sealing mechanism; the speed control mechanism is composed of a motor, rotor, etc; the braking mechanism is composed of a braking rubber cylinder and a first extrusion ring; the anchoring mechanism is composed of a rubber conical cylinder, slips, etc; and the sealing mechanism is composed of a sealing rubber cylinder and a second extrusion ring. The second extrusion ring is driven by a hydraulic rod to press the sealing rubber cylinder, causing it to expand and block the pipe wall to achieve sealing. The intelligent maintenance and repair robot inside the pipeline has the characteristics of good speed control response, wide speed range, strong ability to pass bends, stable braking process, and high sealing reliability.

Abstract: The disclosure relates to petroleum drilling, specifically a downhole signal receiving and transmitting device. The downhole signal receiving and transmitting device includes a receiving part, a control device, a mechanical assembly and a transmitting mechanism. The receiving part receives a signal transmitted by a lower end instrument, and the control device process the received signal, controls a motor to drive a rotating sleeve, and the mechanical assembly performs work. The mechanical assembly drives a mandrel to rotate a rotor continuously and regularly. When rotating, the flow area of the rotor and a stator changes to produce continuous pulses. The pressure waveform changes are monitored on the ground, and the measurement data are calculated by decoding.

Abstract: A preparation method of the microcapsules for low-temperature well cementation to be used to control cement hydration heat includes: (S1) a shell material, and added into deionized water, then the resultant mixture being stirred in a thermostat water bath so as to completely dissolve it into a homogeneous and stable shell material solution; (S2) a core material and an emulsifier being put into a three-necked flask and stirred in a thermostat water bath so as to uniformly emulsify and disperse them, forming a stable oil-in-water core material emulsion, while adjusting the pH value of the emulsion with a pH adjuster; (S3) the three-necked flask containing the core material emulsion being transferred to a water bath, and then the shell material solution being dropwise added into it with stirring, after reacting, a solid-liquid mixture being poured out so as to naturally cool it to room temperature.

Abstract: Techniques for modeling subterranean characteristics by combining physical and numerical simulations using limited amounts of subsurface full diameter core samples via orthogonal experimentation schemes. Systems and methods applying synchronous fitting and prediction of physical simulation and numerical simulation to obtain the equivalent permeability of fracture cells in numerical simulation, to provide a basis for assigning a value to the equivalent fracture cell permeability during numerical simulation. According to the specific subterranean reservoir characteristics, the water invasion orthogonal experiments are completed by combining physical simulation with numerical simulation to analyze the main factors of water invasion in reservoirs.

Abstract: The present invention relates to a bionics-based efficiently transported and packed proppant and preparation method thereof, comprising enhanced fracturing fluid and biomimetic dandelion proppant; the mass ratio of the enhanced fracturing fluid and the biomimetic dandelion is: 1-2:100-400; the 100 pbw of enhanced fracturing fluid includes 0.1-1 pbw of drag reducing agent, 0.01-0.1 pbw of cleanup additive, 0.2-0.8 pbw of clay stabilizer, 0.01-0.05 pbw of bactericide, 0.01-0.2 pbw of nanoparticle enhancer, and water; the biomimetic dandelion proppant consists of modified proppant and modified fiber, and the mass ratio between the modified proppant and the modified fiber is 99-99.9:0.1-1.

Abstract: The invention discloses a parallel device and method for high-precision determination of sulfur solubility under multiple influencing factors, and the device comprises an elemental sulfur absorption system, an elemental sulfur saturation system and a sulfur content determination system. The elemental sulfur absorption system is used to remove the dissolved elemental sulfur in the sour gas. The elemental sulfur saturation system is arranged in parallel to saturate sour gases at different temperatures and pressures at the same time. The elemental sulfur absorption system and the elemental sulfur saturation system are arranged in parallel. The sulfur content determination system is used to determine the total sulfur content of the parallel elemental sulfur saturation system and the elemental sulfur content in the sour gas after absorbing the elemental sulfur under the same conditions.