1176 results about "Carbonate rock" patented technology

The invention provides a gas pool prediction method and system of a carbonate reservoir based on pore structure characteristics. The method comprises the following steps: collecting a rock sample of a target reservoir section of the carbonate reservoir; authenticating geological thin sheets of the rock sample so as to obtain rock basic parameters comprising the rock constituents, the pore shape, the surface porosity and the sedimentary phase belt; carrying out pore permeation measurement on the rock sample so as to obtain pore permeation basic parameters comprising the porosity, the permeation rate and the density; constructing a rock bare-bone model according to the rock basic parameters, the pore permeation basic parameters and a differential equivalent medium model; carrying out fluid replacement on the rock bare-bone model so as to generate a rock physical plate; acquiring prestack seismic inversion data of the carbonate reservoir; intersecting the prestack seismic inversion data and the rock physical plate, thereby obtaining the prediction results of the porosity and the gas saturation of the carbonate reservoir. The accurate quantitative gas pool prediction is realized.

The invention provides an analysis method of the corrosion action and the corrosion effect of a carbonate rock. The method comprises the following steps: detecting petrologic parameters, geological fluid characteristics and geological background parameters of a reservoir stratum of the carbonate rock; selecting a plunger sample, and preparing the plunger sample into a diagenetic fluid; performing weighing, physical property analysis, CT scan analysis and microscopic property analysis on the sample before experiment; performing a corrosion simulated experiment on the carbonate rock, and collecting the reaction generated liquid; performing the physical property analysis, the CT scan analysis and the microscopic property analysis on the sample after experiment; analyzing the content of Ca<2+> and Mg<2+> of the generated liquid; analyzing the corrosion action of the carbonate rock under different controlling factors, determining a three-dimensional structure and a microcosmic pattern of representation of a corrosion hole of the carbonate rock, and quantitatively assessing the corrosion hole of the carbonate rock and the communicated property evolution. By the method, the corrosion action and the corrosion benefits of the carbonate rock from an earth surface to the deep burying environment can be analyzed, and more accurate analytical data is provided for assessing and forecasting the favorable reservoir stratum of the carbonate rock.

The invention discloses a method for constructing a multi-scale digital rock core based on fusion of a CT scanned image and an electro-imaging image. The method is characterized by extracting a large-scale pore and rock skeleton from the electro-imaging image, calculating partial porosity distribution and pore dimension distribution thereof, and constructing a large-scale three-dimensional digital rock core in radial direction; meanwhile, extracting a small-scale pore and rock skeleton from the CT scanned image, calculating partial porosity distribution and pore dimension distribution thereof, and constructing a small-scale three-dimensional digital rock core in depth longitudinal direction; and selecting horizontal sections, the depth of which are same, of the large-scale three-dimensional digital rock core and the small-scale three-dimensional digital rock core respectively, fusing the horizontal sections to generate a multi-scale two-dimension slice having small-scale pores and large-scale cracks and holes, and constructing a three-dimensional digital rock core through the multi-scale two-dimension slice, thereby solving the problem of constructing a multi-scale three-dimensional digital rock core of unconventional reservoir of shale, tight sandstone and carbonate rock and the like, and enabling the digital rock core module to be same with the actual rock to the largest degree.

The invention provides a fissure-cave type carbonate-reservoir reservoir body modeling method, and belongs to the field of carbonate reservoir exploitation geology. The method comprises the steps of (1) distinguishing karst cave reservoir body development segment in a single well; (2) building karst zone models along the vertical direction, building ancient landform unit distribution models in a plane; (3) respectively imitating three-dimensional distribution of the karst cave reservoir body in different karst zones and different ancient landform units, obtaining a three-dimensional distribution model of the karst cave reservoir body of a modeling target stratum; (4) counting development occurrence of a fissure reservoir body and single-well fissure development density; and (5) under control of a fault, building a three-dimensional discrete distribution model of the fissure reservoir body. According to the fissure-cave type carbonate-reservoir reservoir body modeling method, accuracy of the class of reservoir modeling is improved, a true condition of the reservoir is approached in a more objective mode, and important practical significance is provided for exploitation of the reservoir.

The invention provides a complicated rock core preparation method based on CT scanning and 3D printing. Based on a combined technology of CT scanning and 3D printing, the reappearance of an underground rock pore structure characteristic is realized, and the visualization of oil-gas-water distribution inside a rock core can be achieved. Through a 3D printing technology, the visualization and actualization of the digital rock core and a network model can be achieved, and the underground core pore structure can reappear in a real object form. More importantly, with the continuous input and development of unconventional oil-gas fields such as carbonate rocks, shale oil and gas and compact oil and gas, the complicated rock core preparation method has the advantage that by using the combined technology of CT scanning and 3D printing, a new thought and method is provided for representation and preparation of special rock cores.

An oil or gas well penetrating a subterranean formation, such as a carbonate formation, is treated with a well treatment fluid which contains an organic ester. The fluid may be an oil-in-water emulsion of the organic ester and an emulsifier or a homogeneous solution of organic ester and a water/mutual solvent solution. Acid is produced in-situ by hydrolysis of the organic ester.

The invention discloses a fracture-cavern type carbonate hydrocarbon reservoir three-dimensional geological modeling method. The method comprises a step A of modeling block division. In the step A, a fracture-cavern is first divided. Then a hydrocarbon reservoir is divided. A flow unit is further divided. A three-dimensional geological model is further set up according to the flow unit division blocks. The method also comprises a step B of modeling category classification. In the step B, at least a matrix category and a crack category are divided. Step-by-step modeling operations are further performed. The method also comprises a step C of matrix modeling phase-splitting. In the step C, the matrix is divided into a plurality of reservoir body types. Reservoir facies are further divided in line with the reservoir body types. The three-dimensional geological model of each reservoir facies is respectively established. The method further comprises a step D of fracture classification. In the step D, fractures are classified according to different dimensions. Fracture models with different dimensions are further established step by step. The method further comprises a step E of model merging. In the step E, established matrix and fracture three-dimensional geological models are merged in an equivalent way to finally set up a fracture-cavern type carbonate hydrocarbon reservoir three-dimensional geological model. The three-dimensional geological model established through the method can satisfy demands of development scheme designs, development scheme implementation, development dynamic analysis, etc.

An apparatus and method for determining a parameter of interest of a formation composed of carbonate rock. A nuclear magnetic resonance (NMR) sensor assembly produces a pulsed RF field designed for obtaining measurements indicative of the parameter of interest of the formation. A downhole processor processes the measurements for obtaining BVI and BVM using a cutoff time based on classification of the carbonate. Further processing is done to estimate the permeability of the carbonate.

The present invention provides a physical simulation experiment device of fracture-cavity carbonate reservoir hydrocarbon charge. The experiment device comprises a fracture-cavity model, an experiment stand with windows, a wall rock and a camera monitoring system; the fracture-cavity model comprises simulation caves in different sizes and simulation fractures in different sizes; the simulation caves are connected to one another via the simulation fractures; the fracture-cavity model is arranged inside the experiment stand with windows, and the simulation caves of at least one side of the fracture-cavity model are visual through the windows of the experiment stand; a surrounding of the wall rock is arranged around the fracture-cavity model to simulate a formation of fracture-cavity carbonate reservoir; the camera monitoring system is used for measuring and adjusting changes in flow rate and pressure in a charge process, and recording an image of fracture and cave in the charge process displayed in the windows. The present invention further provides a physical simulation method of fracture-cavity carbonate reservoir hydrocarbon charge, which uses the above-mentioned experiment device. The present invention can obtain regularities of distribution of oil, gas and water through parameters such as karsts, fractures, density of cruel oil, and oil, gas and water distribution and the like.

The invention provides a method for identifying and interpreting carbonate rock ancient karst reservoir layer three-dimensional structure. Steps of identifying a single well cave preferably comprise that: according to a cave growing segment with definite rock core and electric imaging well logging information, conventional well logging response characteristics of the cave growing segment are summarized; cave sensitive well logging parameters are preferably selected via a well logging parameter intersection method, and an identification graph plate is established; a multi-parameter normalization weighting method is utilized to establish a cave identification function; steps of identifying an inter-well cave preferably comprise that: a synthetic seismic recording method is utilized toward each single well to calibrate a cave interpreting result of a depth domain to an acoustic inversion data volume of a time domain; then threshold values of a cave segment and a non-cave segment are confirmed so that the inter-well cave is effectively identified; continuous tracking is performed along the middle of caves which are large in scale and great in continuity so that a three-dimensional tracking layer is obtained, an average value of 2ms acoustic save impedance around the tracking layer is computed, and thus a three-dimensional space growing position of an ancient karst reservoir layer is obtained.

The invention discloses a high-flow-conductivity acid fracturing method for carbonate rock reservoirs, and belongs to the field of reservoir reconstruction technologies. The high-flow-conductivity acid fracturing method includes applying acid fracturing processes for corroding crack by acid fluid and hydraulic fracturing processes for filling the crack with added sand in a combined manner, to be more specific, forming the crack in the carbonate rock reservoirs by the aid of non-reactive ahead fluid and reducing the surrounding temperatures of wall surfaces of the crack; injecting high-concentration acid fluid systems to corrode the wall surfaces of the artificial crack and forming uneven grooves in the wall surfaces of the crack by means of corroding to allow the crack to have certain flow-conductivity after the crack is closed; enabling high-viscosity sand-carrying fluid to carry proppants and flow into crack systems and filling the crack with the high-viscosity sand-carrying fluid to further improve the flow-conductivity of the crack. The high-flow-conductivity acid fracturing method has the advantages that the high-flow-conductivity acid fracturing method is reasonable in design, simple in process and convenient to implement in fields, the high-flow-conductivity crack systems with the acid-corroded crack and crack closing supporting functions can be formed, oil and gas flow resistance can be reduced, the acid fracturing reconstruction effects can be improved for the carbonate rock reservoirs, and the high-flow-conductivity acid fracturing method can be widely used for acid fracturing reconstruction construction for limestone, dolomite and carbonate rock oil and gas reservoirs with mud.

The invention relates to a reservoir shear wave velocity prediction method based on rock physics. The method comprises the steps that (1) supposing that the bulk modulus, the shear modulus and the density of a destination interval mineral are unknown constants, the error between a longitudinal wave velocity and a measured longitudinal wave velocity is acquired according to equation modeling, and the error between the acquired density and the measured density is calculated; (2) according to the minimum error criterion, the bulk modulus, the shear modulus and the density of a mineral component are inverted through a genetic algorithm; (3) and the shear wave velocity is calculated. According to the step (1), supposing that the elastic modulus of each rock component is an unknown constant in a reservoir logging curve section, the objective function of the inversion of the logging curve can be defined that a superscript M represents a simulation longitudinal wave velocity, O represents a logging observation longitudinal wave velocity, and w Rho and w rho represent normalized weighted coefficients; and the objective function is a nonlinear function of the bulk modulus, the shear modulus and the density of each mineral component. The method can be applied to a sand shale reservoir, and carbonate rock and other complex reservoirs.

The present invention relates to a method to enhance oil recovery from a hydrocarbon reservoir. One aspect of the invention includes injecting high salinity water into the reservoir followed by alternating the injection of low salinity water and gas.

The invention relates to a pumping stop sand setting fracture-height-controlling acid fracturing process method applicable to a carbonate reservoir. The method comprises the following work procedures that before the normal fracturing, low-viscosity slickwater is adopted for fracture making, and the initial fracture height is controlled; then, after the slickwater enters the stratum in a way of carrying support agent sand, the pumping stop is adopted for prompting the support agent sand to be settled near a fracture opening, so that each stage of support agent sand shields the back section in advance, a high-intensity artificial separation layer is formed, the stress state is changed, and the goal of effectively controlling the lower fracture height extending to prevent the communication with the lower part water body is achieved; low-viscosity fracturing fluid is injected for fracture making at a stable discharge capacity; after the fracturing fluid enters the stratum, acid liquid is injected for etching the stratum, and high-flow-guide capability artificial fractures are formed; after the acid liquid is extruded into the stratum, the pumping is stopped for measuring the pressure drop, and the construction is completed. The process has the advantages that the artificial separation layer can be formed, the fracture height vertical direction extending can be controlled, the stress state is changed, and the goals of effectively controlling the lower fracture height extending and preventing the communication with the lower part water body are achieved.

The invention relates to a dynamic reserve calculation method and system for a fracture and cave type carbonatite oil reservoir fracture and cave unit. The method comprises a fracture and cave unit type division step, a material balance equation simplification step and a dynamic reserve calculation step. According to the method, firstly, the driving types of the fracture and cave unit are divided according to the communication relationship between the fracture and cave unit and a water body; then, a simplified material balance equation is obtained according to different driving types; then, the dynamic reserve calculation parameters in the material balance equation are optimized by combining production dynamic data through the combined relationship of the ground crude oil density, the natural gas relative density and the gas-oil ratio and the relationship between the elasticity modulus and the porosity; and the dynamic reserve in the dynamic reserve calculation parameters is calculated. The method and the system have the advantages that the precision and the accuracy of the dynamic reserve calculation result are improved; and the basis is provided for the oil reservoir development and exploration and the engineering layout.

A drilling fluid system using retarded acid systems such as gelled acid (VES or polymer) and/or emulsified acid to drill carbonate formations (calcite and dolomite). Foamed acid may be used in low abnormal pressure carbonate reservoirs. The drilling fluid system permits drilling a target hydrocarbon-producing formation with zero-invasion of the drilling fluid system. A method for using the drilling fluid system for fluid loss control during drilling operations.

The invention discloses a fracture-cave type carbonate reservoir waterflooding oil replacement recovery method, comprising the steps: 1, pilot flooding; in case of inadequate fracture-cave type reservoir elastic energy, pilot flooding is implemented within a cycle prior to normal waterflooding to determine well positions suitable for waterflooding oil replacement, and then waterflooding speed is determined according to the type of a reservoir body; 2, a proper amount of high specific gravity liquid having larger specific gravity than crude oil and insoluble with the crude oil is injected into the reservoir in order to fill in formation voidages and restore formation pressure; 3, well closing, replacement of the oil and the high specific gravity liquid is implemented by means of gravitational differentiation of the oil and the high specific gravity liquid, and the high specific gravity liquid sinks to the lower part of the reservoir body to form secondary bottom water, thereby driving oil upwards and lifting oil-water interface; and 4, well is opened for oil recovery when wellhead pressure is recovered to basically stable level. According to the invention, the replacement of crude oil and oilfield sewage is implemented by injecting the high specific gravity liquid insoluble with crude oil, such as the oilfield sewage, into oil well, and the crude oil and the oilfield sewage are converged at the upper part of fracture cavity or at the bottom of higher well in order to achieve oil recovery once again.

The invention provides a method for calculating the fracture pressure of ultra deep well formations. The method is based on an elastic theory, a pore elastic theory and a thermoelasticity theory, various factors which can influence the calculation precision are comprehensively taken into consideration, and compared with the calculating method of the prior art, the method is utilized for greatly increasing the calculation precision. The difference between a calculation result obtained by a fracture pressure prediction model of the method and the fracture pressure obtained by calculating according to practical field log data is within 10%. The method is particularly suitable for carbonate rock ultra deep well formations.

The invention provides a method for establishing a large-sized karst cave reservoir body distribution model of a fractured-vuggy carbonate rock reservoir, and belongs to the field of three-dimensional geologic modeling of carbonate rock reservoirs. The method comprises the following steps of: (1) identifying a large-sized karst cave reservoir body development section on a single well, wherein the large-sized karst cave reservoir body development section is an interval with large-sized karst cave reservoir bodies; (2) establishing a karst zone model in a perpendicular direction, and establishing a palaeogeomorphological unit distribution model on a plane; and (3) simulating the three-dimensional distribution of the large-sized karst cave reservoir bodies in different karst zones and palaeogeomorphological units respectively to obtain a three-dimensional large-sized karst cave reservoir body distribution model of a modeling target stratum. The control effect of a karst development mode on the distribution of the large-sized karst cave reservoir bodies is taken into a full account, the constraints of geological laws are enhanced in a modeling process, and the modeling accuracy of the large-sized karst cave reservoir bodies of carbonate rocks is improved.

The invention relates to a device and a method for establishing a double-porosity carbonate reservoir physical model. The device comprises a rock sample interior structure scanning system, a data processing and display system, a 3D (three-dimensional) rapid prototyping printer and thermal drying equipment, wherein the rock sample interior structure scanning system is a basic data acquisition module in the device for manufacturing the double-porosity carbonate reservoir physical model and can reproduce interior structure characteristics of a carbonate reservoir in a lossless and true manner; the data processing and display system is used for receiving and storing 2D (two-dimensional) slice image data, which are obtained by the rock sample interior structure scanning system, of a to-be-detected rock sample; the 3D rapid prototyping printer is connected with the data processing and display system and used for realizing establishment of the physical model of the rock sample adopting a double-porosity structure; and the thermal drying equipment is used for heating the physical model manufactured by the 3D rapid prototyping printer so as to finish establishment of the physical model. According to the device and the method, the defect that framework properties and the true rock sample differ a lot in traditional establishment methods is overcome.

Disclosed are methods of modeling stimulation treatments, such as designing matrix treatments for subterranean formations penetrated by a wellbore, to enhance hydrocarbon recovery. The modeling methods describe the growth rate and the structure of the dissolution pattern formed due to the injection of a treatment fluid in a porous medium, based on calculating the length scales for dominant transport mechanism(s) and reaction mechanism(s) in the direction of flow l_X and the direction transverse to flow l_T. Methods of the invention may further include introducing a treatment fluid into the formation, and treating the formation.

The invention discloses a method for forecasting a carbonate reservoir based on forward modeling of a digital geological model, and is characterized by comprising the following steps: in petroleum geological exploration, through a field carbonate geological outcrop collecting and data processing technology and combination with an actually-measured geological section, establishing a three-dimensional digital geological model of an outcrop area, according to an outcrop rock speed analysis chart and a drill speed data, establishing a speed model of the carbonate reservoir with different physical properties on the basis of the three-dimensional geological model, carrying out two-dimensional forward modeling and three-dimensional forward modeling, carrying out offset horning process on earthquake forward modeling data so as to obtain three-dimensional offset data or a two-dimensional offset section of the earthquake forward modeling, establishing reflecting characteristics of different carbonate reservoirs according to response characteristics of the earthquake section, and forecasting the carbonate reservoir. According to the invention, qualitative forecasting of the carbonate reservoir can be realized without a regular earthquake inversion, a large amount of manpower and device resources are saved, reliability and precision of forecasting of the carbonate reservoir in the earthquake are effectively improved, exploration and development risk can be reduced, and benefit is increased.

The invention provides a method for quickly recognizing carbonate formation lithologies while drilling. The method includes the first step that the different lithologies are judged; the second step that rock debris of the different lithologies are sampled and are analyzed through the X-ray fluorescence element logging technology, and the Ca element pulse content and the Mg element pulse content are counted; the third step that rock debris of the different lithology centers are sampled, the Mg pulse content and the Ca pulse content of the different lithology centers are counted, and the average interval between the Mg pulse content and the Mg pulse content at the lithology center and the average interval between the Ca pulse content and the Ca pulse content at the lithology center are calculated; the fourth step that the Ca pulse content average value and the Mg pulse content average value of different lithologies are calculated respectively, then logging lithology recognition standards are obtained, and a lithology interpretation chart is established. The method achieves accurate recognition of the lithologies while drilling, judges that whether a horizontal well track passes through dolomite or not in time, and then provides a scientific basis for the necessity of adjustment of a track of an undrilled well segment and for predicament of the track of the undrilled well segment.

The invention provides a fractural diverting acid-fracturing method for carbonate oil-gas reservoirs. The method includes the steps of 1, injecting 50-5000 cubic meters of fracturing fluid into a stratum at a displacement speed of 2.0-15.0 m<3>/min; 2, injecting 5-100 cubic meters of material fluid into the stratum at a displacement speed of 1.0-15.0 m<3>/min, and allowing pumping at a displacement speed of 0.5-4.0 m<3>/min after the material fluid enters a preset intra-fracture bridge plug; 3, injecting 50-500 cubic meters of fracturing fluid into the stratum at a displacement speed of 3.0-15.0 m<3>/min to allow forced fractural diverting; 4, injecting 20-300 cubic meters of acid fluid at a speed of 2.0-15.0 m<3>/min to allow modification by acid etching; performing at least one operation of steps from 2 to 4. The method has the advantages that multiple diverted acid-fracturing fractures can be formed after repeated multiple of temporary plugging and fracture forming, temporary plugging material degrades after acid-fracturing construction is complete, low pollution is caused to reservoirs, and the method helps improve acid-fracturing efficiency.

The invention relates to a self-born acid composite acid fracturing process for a high-temperature deep well carbonate rock reservoir. The process comprises the following work procedures of: (1) injecting slick water into a stratum through an oil pipe; (2) injecting non-crosslinked fracturing liquid into the stratum through the oil pipe; (3) injecting a self-born acid system into the stratum through the oil pipe; (4) injecting a gelled acid system into the stratum through the oil pipe in a low-displacement mode; and (5) injecting the slick water into the stratum through the oil pipe, wherein the volume proportions of liquid, accounting for the total liquid injected into the stratum, injected in the first to fifth work procedures are shown as follows: the slick water in the first work procedure accounts for 3 to 10 percent; the non-crosslinked fracturing liquid in the second work procedure accounts for 40 to 60 percent; the self-born acid system in the third work procedure accounts for 30 to 50 percent; the gelled acid system in the fourth procedure accounts for 3 to 10 percent; the volume proportion of the slick water in the fifth work procedure is 3 to 15 percent; and the volume unit is m<3>. Through the self-born acid composite acid fracturing process, the flow guide capability is improved by more than 140md.m, and the deep penetration effect of the high-temperature deep well carbonate rock reservoir is obvious.