9 results about "Skin factor" patented technology

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.

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.

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 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.