15 results about "Skin factor" patented technology

This invention discloses a method and related apparatus for calculating the skin factor of oil and gas wells based on resistivity logging. The method includes: acquiring resistivity logging data and well test skin factor data of the target formation in an oil and gas field; establishing a skin factor calculation model based on the resistivity logging data and well test skin factor data; and calculating the skin factor of the well to be logged in the oil and gas field based on the skin factor calculation model. This invention utilizes resistivity logging data and well test skin factor data of the target formation in an oil and gas field to establish a skin factor calculation model, and calculates the skin factor of the well to be logged in the oil and gas field based on this model. This provides more accurate production capacity prediction for the oil and gas field production and development field, and avoids the determination of various process parameters and the calculation process of complex skin factor models, effectively solving the problem of difficulty in determining the skin factor in actual production and development.

The invention belongs to the technical field of sand control well completion in the natural gas hydrate development industry, and particularly relates to a method for constructing a sand control chart of a natural gas hydrate reservoir. Comprising the following steps: 1) carrying out a natural gas hydrate reservoir gravel packing sand prevention long-period simulation experiment by adopting a natural gas hydrate reservoir gravel packing sand prevention long-period simulation experiment device; 2) calculating a gravel layer comprehensive evaluation index based on an experiment result in the step 1); 3) calculating a sand resistance retention coefficient based on an experimental result in the step 1); the construction method comprises the steps of (1) obtaining an experimental result, (2) calculating a blocking skin coefficient based on the experimental result obtained in the step (1), (5) calculating the productivity ratio of the gravel packing sand prevention system based on the blocking skin coefficient, and (6) constructing a sand prevention plate and screening out an area with the optimal sand prevention precision. The construction method of the sand prevention plate is beneficial to achieving long-term efficient development of natural gas hydrates.

This invention relates to a method for determining the contamination level near a wellbore based on a skin factor derived from thermodynamic parameters. The method includes: measuring wellbore parameters and thermodynamic parameters; establishing a pressure relationship equation near the wellbore based on the wellbore parameters and thermodynamic parameters; establishing a temperature relationship equation near the wellbore based on the wellbore parameters and thermodynamic parameters; solving for the skin factor based on the pressure and temperature relationship equations; and determining the contamination level near the wellbore based on the skin factor. This invention can quickly calculate the skin factor from a thermodynamic perspective when the thermodynamic parameters are known, without the need for fitting well test curves, thus improving the efficiency of well test interpretation to a certain extent. The calculation steps are simple and the method is fast.

The present application relates to a kind of fracture type buried hill reservoir skin coefficient system decomposition method, comprising: step A.Combined with the calculation method of various types of dynamic and static skin coefficient of fracture type buried hill reservoir characteristics constitutes total skin;Step B.Based on the test data of test well, total skin coefficient of test well is obtained using pressure recovery well test interpretation method;Step C.According to the well condition of test well, the main dynamic and static skin coefficient constituting total skin coefficient of test well is determined;Step D.The method of step A is used to calculate the skin coefficient type determined in step C, to realize the skin decomposition of test well, and to clarify the composition of various skin coefficients of test well.The present application can accurately obtain the size of various skin coefficients of test well in fracture type buried hill reservoir, and provide guidance for further stimulation operation.

The invention discloses a method for identifying a carbon dioxide leading edge position of carbon dioxide pre-fracturing through high-frequency pressure, and the method comprises the following steps: collecting carbon dioxide pre-fracturing high-frequency pressure data at a well bottom, and carrying out the nondimensionalization of the pressure data; determining inner and outer areas of the composite oil reservoir according to a well testing theory, and calculating mobility and mobility ratio; determining a dimensionless pressure equation and a definite solution condition according to stratum conditions, obtaining a bottom hole pressure expression, and performing inversion to obtain a numerical relationship with dimensionless combination time to make a typical oil line; the curve form is analyzed, and the stratum parameter influence is determined; and determining a carbon dioxide leading edge position. On the basis of a well testing theory and accurate pressure equation derivation, the characteristics of the composite oil reservoir are fully considered, including factors such as fluidity and fluidity ratio of an inner area and an outer area, shaft storage and skin factors and the like, pressure distribution in the oil reservoir and the flowing state of carbon dioxide can be more accurately described through mathematical modeling and analysis, and the analysis accuracy is improved. Therefore, the front edge position of the carbon dioxide can be determined more accurately.

This invention provides a knowledge- and data-driven drilling and completion fluid design expert system, belonging to the field of reservoir protection technology in the petroleum industry. The system includes: a total skin factor calculation module for calculating the total skin factor of a target well; and an optimization module for determining that the drilling and completion fluids corresponding to the target well have good performance and require no optimization design when the total skin factor of the target well is less than or equal to 0; and for optimizing the drilling and completion fluids corresponding to the target well when the total skin factor of the target well is greater than 0, by: determining a target drilling fluid formula based on the permeability and / or structural characteristics of the reservoir corresponding to the target well, and pre-setting drilling fluid formulas corresponding to different permeability and / or structural characteristics; and determining a target completion fluid formula based on the type of completion fluid corresponding to the target well and pre-setting completion fluid formulas corresponding to different completion fluid types.

The application discloses a nonlinear seepage skin factor calculation method, device, equipment and medium. The change relationship between scanning pressure and time is obtained, and each flow section and a pressure recovery section are divided. Based on the flow section and the pressure recovery section data and genetic algorithm initialization factors, preliminary full pressure history fitting is completed. Genetic algorithm automatic iterative search technology is applied to improve the initial full pressure history fitting, and the skin factor corresponding to each flow section is calculated. According to the calculation results, the optimal technology is used to regress and calculate the true skin factor, so that the full-process automation of the skin factor calculation is realized, and the accuracy and scientificity of the reservoir analysis results are improved.

The invention relates to a sand prevention method for establishing a high diversion channel of a loose sandstone reservoir, and relates to the field of downhole operation technology, and the sand prevention method comprises the following steps: S10, reservoir pretreatment: pretreating an oil well to reduce the skin coefficient of a near wellbore zone; s20, sand prevention design and parameter optimization are carried out, wherein sand prevention design is carried out, and parameters are optimized; and S30, sand prevention well management optimization, wherein optimization management is conducted on the sand prevention well, and a corresponding shaft sand prevention mode is selected. The method has the advantages that the contradiction that the near wellbore area and the wellbore are easily blocked after sand prevention of the oil reservoir is solved, and the long-term high and stable yield of the oil reservoir is achieved.

This application relates to the field of petroleum engineering and provides a method and system for optimizing the residual acid flowback time in high-speed water injection oil wells. The method includes: testing the critical concentration of fluoride ions in the acid; obtaining a core sample and placing it in a test pipeline, then injecting acid into the test pipeline; allowing the acid to remain in the test pipeline for a specified duration after injection; obtaining the skin factor of the core sample and the fluoride ion concentration of the acid in the core sample at different test durations; determining the test duration at which the skin factor is minimized and the test duration at which the fluoride ion concentration reaches the critical concentration value; selecting the smaller of these two values ​​as the optimal duration; and performing residual acid flowback at the optimal interval after the well is shut down following acid injection. This reduces damage to the reservoir, improves acidizing efficiency, and overcomes the limitation of existing methods that rely solely on engineers' experience to determine the flowback time.

A horizontal well integrated acidification method considering a permeability spatio-temporal evolution law relates to the technical field of oil and gas development, and comprises the following steps: collecting stratum data of a target horizontal well area, and dividing a target horizontal well into a shaft unit, a stratum unit and a time unit; calculating the equivalent ellipse invasion radius and the equivalent shaft radius of the drilling fluid in each formation unit, the permeability of the formation invasion area after the drilling fluid is injected, the local skin factor, the comprehensive skin factor and the temporary plugging agent filter cake skin factor of each formation unit and the permeability of the formation at any moment in sequence; the flow of any stratum unit at any moment after drilling fluid injection and temporary plugging acidification is calculated, and the drilling fluid injection amount and the acid fluid injection amount of the stratum unit within the specific time range are obtained; according to the method, the difference of the permeability damage zones of the horizontal well is considered, on the basis of determining the specific pollution condition of the drilling fluid to the horizontal section stratum, a better result of implementing the acidification operation is obtained, and the quality of the acidification operation is fully improved.

The application discloses a long-acting injection-increasing process effect evaluation method, and specific steps are as follows: step 1, obtaining the original porosity and the porosity after acidification, the original permeability and the permeability after acidification, the wellbore radius and the reservoir injection unit radius according to geological data, and calculating the porosity variation amplitude and the permeability variation amplitude; step 2, measuring the water absorption index before acidification and the water absorption index after acidification, calculating the injection-increasing multiple and the skin factor after acidification, determining the injection well pressure drop index IPI and the effective days of acidification measures; step 3, performing dimensionless processing on the parameters obtained in step 1 and step 2; step 4, calculating the grey correlation coefficient and the correlation degree; and step 5, calculating the weight coefficient and the decision factor. The method solves the problems that the quantitative evaluation method of the injection-increasing process effect in the prior art is complex and the evaluation parameters are difficult to obtain.

This invention belongs to the field of oil extraction and relates to a method for characterizing the breakthrough point of bio-nano-based unblocking and injection enhancement. The method includes: measuring the porosity and permeability of the core sample; injecting a bio-nano-based unblocking agent using KCl or NH4Cl solution for displacement, and analyzing the breakthrough point of the bio-nano-based unblocking agent; flushing the pipeline with simulated formation water, shutting off the displacement device, injecting the bio-nano-based injection enhancement agent, and measuring the porosity and permeability of the core sample again; dividing the unblocking process into a linear flow model into contaminated and uncontaminated zones, determining the contaminated skin coefficient based on Darcy's formula and the definition of the skin factor, and determining the fluid viscosity in the contaminated zone and the fluid viscosity in the uncontaminated zone at any given time; deriving the relationship between pressure difference and time during the core displacement reaction process based on the fitting relationship between pressure difference and the rising and falling phases of the injected PV number, and the relationship between the unblocking agent propulsion time and the injected PV number; and determining the relationship between fluid viscosity and the unblocking agent injection time based on the relationship between pressure difference and time during the core displacement reaction process.

The application discloses a horizontal well integrated acidification method considering the space-time evolution law of permeability and relates to the technical field of oil and gas development, which comprises the following steps: collecting stratum data of a target horizontal well region, dividing the target horizontal well into wellbore units, stratum units and time units respectively, sequentially calculating the equivalent elliptical invasion radius and equivalent wellbore radius of drilling fluid in each stratum unit, the stratum invasion zone permeability after the injection of drilling fluid, the local skin factor of each stratum unit, the comprehensive skin factor, the temporary plugging agent filter cake skin factor and the permeability of the stratum at any time, combining the above results, calculating the flow of any stratum unit at any time after the injection of drilling fluid and temporary plugging acidification, and obtaining the drilling fluid and acid liquid injection amount of the stratum unit in a specific time range; the application considers the difference of the permeability damage zone of the horizontal well, on the basis of the specific pollution of the drilling fluid to the horizontal section stratum, obtains a relatively optimal result of the acidification operation, and fully improves the quality of the acidification operation.

The application discloses a method for calculating a variable skin factor during screen pipe completion of a gas well, and comprises the following steps: obtaining screen pipe parameters, formation parameters, well parameters and fluid parameters; determining a slot turbulence coefficient, a formation turbulence coefficient and a Forchheimer coefficient; carrying out a solid-phase sulfur dissolution experiment in a gas under formation temperature; determining a total amount of solid-phase sulfur precipitation, a plugging width, a slot internal linear flow non-rate-dependent skin factor, a radial flow non-rate-dependent skin factor, a radial flow inertial resistance coefficient, a slot internal linear flow inertial resistance coefficient, a radial flow non-rate-dependent skin factor, a radial flow inertial resistance coefficient, a screen pipe external radial flow non-rate-dependent skin factor and a screen pipe external radial flow inertial resistance coefficient; and calculating a total screen pipe completion skin factor. The method realizes dynamic and accurate characterization of a skin factor of a high-sulfur gas well, and provides a reliable theoretical basis for gas well productivity evaluation, production system optimization and completion design.

The invention discloses a method and system for automatically and rapidly generating a drilling and completion plug removal scheme, and relates to the technical field of drilling and completion plug removal. According to the scheme, the method comprises the steps of S1, calling basic parameters from a drilling database; s2, outputting a blockage coefficient K by using the classification judgment model and identifying a blockage type; s3, calling a sand prevention and plug removal sequence optimization rule, matching a composite acid, bio-enzyme and surfactant system, and generating an injection scheme through an injection amount calculation formula and a sequence rule; and S4, implementing and verifying. The method has the beneficial effects that the blockage of inorganic scales, organic macromolecules, solid particles and a crude oil mixture can be quickly and accurately judged, and the limitation of empirical judgment is avoided; based on scientific calculation of a pollution coefficient and a treatment radius, reasonable dosing of the medicament is realized; and in combination with sequential optimization of reservoir types and rock cementation indexes and multi-system collaborative injection, the skin coefficient is stably reduced to 0.5 or below, the permeability recovery rate reaches 82%-88% or above, and the blockage removal efficiency and accuracy are remarkably improved.