856 results about "Water flooding" patented technology

A method for designing acid treatments provides for the selection of optimal treatment for well stimulation wherein reservoir characteristics are obtained to further select the reaction kinetic data on the minerals of interests, the treatment to the reservoir is scaled up using a mathematical model and real time damage are computed based on bottomhole pressure and injection rate and compared to that predicted by the mathematical model to adjust the treatment. The model generated facilitates optimization of matrix treatments by providing a rapid quantitative evaluation of various treatment strategies for a formation. Stimulation with non-traditional fluid recipes containing mixtures of inorganic and organic acids, and chelating agents can be readily computed. The computed values can then be used in an economic model to justify the additional costs associated with the use of the non-traditional fluids. Apart from optimizing matrix treatments, the method can be used as a development tool for new fluid systems, as a tool for prediction and removal of inorganic scale and for fluid compatibility testing such as that required in water flooding projects.

Apparatuses and methods suitable for (i) measuring lithological or petro-physical properties of reservoir core sample including shale rock; (ii) evaluating the degree of formation damage caused by foreign fluid into formation; (iii) conducting dynamic experiments, such as water flooding, chemical solution flooding, and supercritical CO2 injection to displacing oil tests; (iv) simulating physical radial flow experiments using reservoir core sample(s) at conditions of temperature up to 150° C. and pressure up to 6000 psi, are provided involving radial flow through the core sample(s) having at least partially hollow centers in an axial direction, up to annular axial cross-sections.

A method for predicting the development index of pulsed periodic water flooding in multi-layer reservoir is based on mathematical analysis and optimization theory, synthesizes the static reservoir factor and dynamic development factor, fully refers to and applies coring, secondary interpretation, exist monitoring data, etc. to establish a split calculation method and reasonable injection distribution and injection allocation models. The sub-injection and injection allocation models are respectively formed into software, which can transfer the relevant data from the production database of the research block. The injection allocation quantity of each well and each layer in the block is automatically calculated by the injection allocation model. Through the calculation of separate injection model, the separate injection intervals of water injection wells are automatically given. The invention divides data display, service processing and data storage into different layers. The method maintains the relative independence between the layers, and is especially suitable for the development of large-scale systems. Once the user business rules change, the system has good adaptability, and theworkload of later revision and maintenance is small.

The invention relates to a modified expansion-slowing particle profile controlling agent used for deep profile controlling and flooding of an oilfield and water plugging of an oil well, a preparation method thereof and application in the field of oil exploitation. The modified expansion-slowing particle profile controlling agent comprises the following components in parts by weight: 4-20 parts of a water-soluble monomer, 10-50 parts of an oil-soluble monomer, 0.01-1 part of a water-soluble cross-linking agent, 0.02-2 parts of an oil-soluble cross-linking agent, 1-10 parts of a surfactant, 0.05-0.5 part of a water-soluble initiating agent, 0.001-0.25 part of an oil-soluble initiating agent, 0.05-0.5 part of a coupling agent, 0-5 parts of alkaline and 30-70 parts of de-ionized water. The modified expansion-slowing particle profile controlling agent overcomes the disadvantages of the conventional expansion type particles that water-absorbing expansion speed is high, the particles after expanding are too hard, and the particles cannot be used for deep profile controlling of the oilfield; the particle profile controlling agent is applied to water plugging of the oil well and deep fluid diversion of the oilfield with a high water content, improves displacement effects of water flooding, polymer flooding and surfactant flooding, and increases recovery efficiency of oil accumulation.

The invention provides a fracture-vug type oil reservoir water-flooding development effect evaluation method. The fracture-vug type oil reservoir water-flooding development effect evaluation method comprises the steps that fracture-vug units to be evaluated are divided into a plurality of injection and production well sets; the well control coefficient of each injection and production well set is calculated, and the well control effect interval of each well set is determined combined with a corresponding preset well control coefficient index; the water-flooding recovery efficiency and the oil exchange rate of per ton water of each injection and production well set are calculated, and the development effect interval of each well set is determined combined with a corresponding preset development coefficient index; the cumulative water content and the water storage rate of each injection and production well set are calculated, the judging that whether water channeling exists or not is performed according to the cumulative water content, a water storage effect interval is determined combined with a preset water storage rate index; the non-dimensional flexible yield ratio, the single reservoir pressure drop and the artificial water-flooding index of each injection and production well set are calculated, the natural energy interval of each well set is determined combined with a corresponding preset natural energy index, a water-flooding effect interval is determined combined with a preset artificial water-flooding index. The fracture-cavern type oil reservoir water-flooding development effect evaluation method fully reflects the water injection effect of the injection and production well sets and the reason of achieving the effects, and therefore the foundation and the basis and the pertinence of the provided adjustment measure are better achieved.

The invention aims at providing a diversified engineered safety system for a nuclear reactor. The diversified engineered safety system comprises a loop passive residual heat removal subsystem, a secondary-side passive residual heat removal subsystem of a steam generator fed with water by gravity, a total-pressure active residual heat removal subsystem, a low-pressure passive safety injection subsystem and a water-flooding and air-cooling combined passive containment cooling subsystem. All the subsystems can independently run or can be matched with one other, and parallel and redundant complete residual heat removal channels with diversified principles are built between a reactor core and an ultimate heat sink, so that a main system and the reactor core of the reactor can be quickly and efficiently cooled and the reactor can quickly enter a safety state in the initial stage of an accident. Even if one subsystem has a fault, other subsystems can still complete a complete and effective residual heat removal function for guaranteeing that the reactor is effectively cooled.

The invention provides a placing method of a self-simulating lateral-displacement horizontal well of a super-low permeability tight reservoir. The placing method comprises the following specific steps: determining a main force construction layer section; determining the positions of horizontal wells, water injection wells and artificial fractures; determining a well row direction of the horizontal wells; determining a well spacing between the horizontal wells; determining a distance between the rows of the horizontal wells; determining the length of each horizontal well; determining an offset distance of each water injection well; determining a length of each artificial fracture of each water injection well; and injecting water; scattered water injection in the past is changed into linear water injection, and in case of the same water injection amount, a water injection pressure is reduced so that secondary opening of a natural fracture generated in the water injection process can be avoided and a risk of fractured water flooding can be reduced; elastic solution gas drive in a region between the artificial fractures is converted to water drive and a fracture dominant direction of a local region is kept consistent so that early-phase water breakthrough can be avoided and an energy supplementing level can be increased. Row water injection displacement is formed through appropriate fracturing of the directional water injection wells, leading to the advantages that layered water injection can be realized and maximum draw-on in a longitudinal direction can be realized, compared with taking the horizontal wells as the water injection wells.

Nanoparticles for use in the treatment of a well have a magnetic core of iron, nickel or cobalt or an alloy thereof; a carbon shell encapsulating the magnetic core; at least one organic functional group on the surface of the carbon shell through covalent bonding; and a coating of amorphous carbon nitride encapsulating the functionalized carbon shell. The nanoparticles may be used to identify fluids produced from the reservoir, identify the zone within the reservoir from which recovered fluid is produced, in water flooding to determine water breakthrough in the production well and to identify those injection wells from which breakthrough water originates.

The invention provides polymer microspheres for high temperature hypersalinity reservoir deep profile control and a preparation method thereof. In the method, based on the method that photopolymerization is used to prepare the polymer microspheres, heat and salt resistance polymer materials such as sodium 3-acryloylamino-3-methyl butyrate, 2-acryloylamino-2-methylpropane sulfonic acid, acrylamide monomer and the like and water-soluble anionic monomer are adopted and dispersant and cross-linking agent are added as so to form oil-water mixed emulsion in the mixed medium of surfactant and solvent; then initiator is decomposed by ultraviolet through photopolymerization under controllable temperature so as to initiate emulsion polymerization and 50-500nm of microspheres are formed. The invention utilizes the ability of microspheres that microspheres can be dispersed in arbitrary concentration and injected in the water and can gradually swell after entering in depth of the formation to plug the pore throat so as to effectively plug the high permeable strip of the formation, expand the water swept volume, significantly increase crude oil recovery of water flooding reservoir and is applicable to high temperature hypersalinity reservoir deep profile control.

The invention discloses an experimental device and an experimental method for hydrothermal catalytic pyrolysis in a heavy oil layer by means of ultrasonic wave, wherein the experimental device comprises a core holder, a ring pressure supply device, a water storage tank, an oil storage tank, an ultrasonic transducer, an ultrasonic generator, a liquid container, a catalyst, a reaction assistant storage device and a constant temperature box; a steam generator is arranged on a water pipe between the water storage tank and the core holder; the experimental method comprises the following steps: 1, pre-treating tested core; 2, performing water-flooding experiment and measuring original water-flooding permeability of the tested core; 3, performing oil-flooding experiment and measuring original oil saturation degree of the tested core; 4, performing hydrothermal pyrolysis simulation experiment; and 5, preparing data. The experimental device and the experimental method have rational design. The device is convenient to install and distribute, has complete function, is convenient to use and operate and has good usage effect. The problems that the prior normal steam thermal driving heavy oil has easily-rebounding viscosity and short measure validity period, and the normal hydrothermal catalytic pyrolysis technology has limited effect during the heavy oil recovery process can be solved.

The invention discloses an industrial procedure for identifying preferential seepage channels of oil and gas reservoirs of clastic rock. The industrial procedure includes steps of 1), dividing n development phases and dividing wells into n groups according to the development phases of well drilling time; 2), dividing data grids of research areas; 3), interpolating permeability parameters of well points of the well groups 1 to obtain permeability planar distribution grids of the development phases 1; 4), sequentially acquiring permeability planar distribution grids R<1>, R<2>, ..., and R<n> of the n development phases by the aid of a method implemented in the step 3); 5), computing a variation coefficient of a permeability value of each grid point by the aid of results obtained in the step 4) so as to obtain variation coefficient grids P; 6), subtracting the R<1> from the R<n>, assigning values of 1 to the grid points with positive difference values and assigning values of -1 to the grid points with negative difference values to obtain grids T; 7), multiplying the grids P by the grids T to obtain grids Q, drawing contour maps of the grids Q, and utilizing regions larger than 0.3 in the contour maps as the preferential seepage channels. The variation coefficients of the permeability values of the grid points change along with change of the development phases. The industrial procedure has the advantage that oilfield water-flooding development and remaining oil prediction can be guided.

Hydrophilic polymer particles have been obtained using polyacrylamide, xanthane, maleic anhydride polymers, allylamine, ethyleneimine, and oxazoline as core polymers. Then, hydrophobic polymers shells have been produced on the core-side using styrene, styrene copolymers, polyvinyl state, polysolfune, polymethyl methacrylate, and polycyclohxyl methacrylate by in-situ polymerization of monomer as method one and inverse emulsion process as method two. These particles can release hydrophilic polymers at oil-water interface at the reservoir temperature where the water flooding should have the maximum viscosity. So, active materials cause to decrease the mobility ratio of water to oil in the reservoirs and on the other hand, plug the swept porosities and prevent to act the water fingering process.

A method for designing acid treatments provides for the selection of optimal treatment for well stimulation wherein reservoir characteristics are obtained to further select the reaction kinetic data on the minerals of interests, the treatment to the reservoir is scaled up using a mathematical model and real time damage are computed based on bottomhole pressure and injection rate and compared to that predicted by the mathematical model to adjust the treatment. The model generated facilitates optimization of matrix treatments by providing a rapid quantitative evaluation of various treatment strategies for a formation. Stimulation with non-traditional fluid recipes containing mixtures of inorganic and organic acids, and chelating agents can be readily computed. The computed values can then be used in an economic model to justify the additional costs associated with the use of the non-traditional fluids. Apart from optimizing matrix treatments, the method can be used as a development tool for new fluid systems, as a tool for prediction and removal of inorganic scale and for fluid compatibility testing such as that required in water flooding projects.

The invention relates to a fracture-cavity type oil deposit analyzing method for water-flooding development and application thereof. According to the method, history matching is conducted on a first geologic feature parameter of multiscale reservoir bodies constructing a multiscale reservoir body distribution conceptual model to obtain a second geologic feature parameter of the multiscale reservoir bodies constructing the finely drawn multiscale reservoir body distribution geologic model. In history matching, the independent representation multi-sided conductivity is adopted for dealing with the influence caused by connection position differences of different side fractures and caves on the oil water flowing rule; the virtual time step is adopted for reflecting the oil water replacement momentary balancing effect caused by oil water density difference; for anisotropy characters of the fractures, the tensor permeability of an arbitrarily fracture of the space is obtained by the adoption of conversion of a geodetic coordinate system and a space coordinates system. The fracture-cavity type oil deposit analyzing method for the water-flooding development is used for conducting fracture-cavity type oil deposit water-flooding development and decisions, the geologic model is more accurate, the flowing rule and the oil-displacement mechanism are more complete, and optimized decision through technologies and development effect predication are more accurate and reliable.

The invention provides a novel water flooding layer logging evaluation method applying a three parameters self-consistent iterative algorithm. The method comprises the following steps: confirming the logging identifying standard of the water flooding levels according to the relationship of the known water flooding levels and the logging response, preliminarily distinguishing the water flooding level of the evaluation layer according to the standard, then valuing a water out flow rate according to the water flooding level, taking the water out flow rate, the water saturation and the mixture formation water resistivity as iterative variable, taking two statistics relationship of the water saturation and the water out flow rate, and the mixture formation water resistivity and the water out flow rate as iterative computation relations, taking the permissible deviation of the two front and back times of calculating water content as the iterative control conditions to carry out the iterative computation, and confirming the parameters of water content, mixture formation water resistivity and the water saturation of the target layer and the final water flooding level according to the final calculating result of the iterative computations.

The invention belongs to the technical field of oil exploitation and particularly relates to a calculation method for predicating recovery percentage and water cut of an oil field. The method for predicting the recovery percentage and water cut of the oil field comprises the following steps of: (1) obtaining a water-oil mass ratio: Qw / Qo, i.e. Fg; (2) obtaining the initial oil saturation: Soi; (3) testing the irreducible water saturation: Swi; (4) obtaining a crude oil volume factor Bo; (5) putting the above parameters into a formula as shown in the specification so as to obtain a relationship between the water cut and the recovery percentage. According to the method for predicting the recovery percentage and water cut of the oil field provided by the invention, a universal method applicable to water-flooding development of reservoirs with high-permeability, low-permeability and ultra-low permeability is obtained, and the actual changing rule of the water cut and recovery percentage of reservoirs and the percolation characteristic representation of the oil reservoirs of different types can be reflected, therefore the method is fit for the practical situation better; furthermore, the development index prediction precision can be improved, therefore the method has an important practical significance on the production practice of the oil fields.

The embodiment of the invention provides a low-permeability oil reservoir water flooding wave and coefficient evaluation method, which comprises a longitudinal wave and coefficient evaluation method and a plane wave and coefficient evaluation method, wherein the longitudinal wave and coefficient evaluation method comprises the following steps that: longitudinal wave and coefficient main control factors of a low-permeability oil reservoir are determined; a sand body communication coefficient is introduced for modifying longitudinal waves and a prediction formula; sensitivity analysis is carried out; and a plate is drawn, so that the looking-up is convenient. The plane wave and coefficient evaluation method comprises the following steps that: through coordinate conversion, the permeability of the low-permeability oil reservoir during anisotropy is converted into the permeability during isotropy; the water flooding wave and region area is determined by considering the anisotropy and the starting pressure gradient; the well control region area is determined, a ratio of the water flooding wave and region area to the well control region area is determined to be the plane wave and coefficient of the low-permeability oil reservoir. The embodiment of the invention realizes the water flooding wave and coefficient evaluation of the low-permeability oil reservoir, and the basis and the regulating direction are provided for low-permeability water flooding yield improvement.

The embodiment of the invention provides a method and a system for identifying a water flow dominant channels of a high-water-content oil field. The method comprises the following steps of: acquiring parameters of between oil wells and water wells taking layer as a unit of the high-water-content oil field; performing statistical analysis on the parameters to obtain the proportion of the parameters in falling intervals; generating a model corresponding to the parameters according to the proportion of the parameters in the falling intervals; and identifying the water flow dominant channels among layers of the oil wells and the water wells according to the model corresponding to the parameters. A normal distribution model of each parameter is formed by acquiring the parameters related to thewater flow dominant channels; and an identification system for identifying the water flow dominant channels is formed by establishing an identification standard of the water flow dominant channels and applying the normal distribution model of each parameter so as to improve the water flooding development effect of the high-water-content oil field.

Purpose of the invention is to raise performance of anti- error code in multi-user MIMO system. The method includes steps: base station obtains channel matrix and noise power of each user's terminal; using channel matrix and noise power of each user's terminal and prearranged precoding method calculates equivalent SNR of each user's terminal; determining self adaptive modulation parameter table from equivalent SNR; using water flooding method determines value of power distribution based on equivalent SNR of each user's terminal; calculating new SNR of each user's terminal from noise power and value of power distribution of each user's terminal, and determining corresponding mode of modulation from the self adaptive modulation parameter table based on new SNR; redistributing power for users' terminals in same modulation mode according to mode in same SNR so as to obtain final distributed power for each user's terminal, sending data from antenna based on final distributed power and mode.

The invention belongs to the field of oilfield chemistry, and particularly relates to a reinforced gel dispersion deep profile control and flooding agent for low-permeability high-temperature high-salt oil reservoirs. The reinforced gel dispersion deep profile control and flooding agent for low-permeability high-temperature high-salt oil reservoirs is composed of the following components in percentage by mass: 0.4-0.6% of functional polymer, 0.4-0.8% of crosslinking agent, 0.2-0.3% of inorganic reinforcer and the balance of water. The average particle size distribution of the reinforced gel dispersion deep profile control and flooding agent is nano or micron size; and the reinforced gel dispersion deep profile control and flooding agent can be used for deep profile control and flooding for low-permeability oil reservoirs, and has favorable deep migration capacity, favorable profile improvement effect and obvious recovery efficiency enhancement effect. The deep profile control and flooding agent can be used for deep profile control and flooding operation of high-temperature high-salt oil reservoirs. The reinforced gel dispersion deep profile control and flooding agent effectively improves the stratigraphic profile, obviously enhances the subsequent water flooding sweep efficiency and further enhances the recovery efficiency.

The invention discloses an oil deposit water-driving exploiting method of an ultra-high water-containing period. The oil deposit water-driving exploiting method solves the problem that the existing water-driving exploiting method of the oil field of the ultra-high water-containing period is poor in effect, adopts a 'two and three combined' exploiting method and particularly comprises: fully utilizing a deployed secondary oil-layer polymer flooding infilled well pattern within about three years before tertiary oil recovery of a secondary oil layer, performing flooding infillled adjusting digging on a first set of polymer flooding layer of the secondary oil layer according to a tertiary oil recovery layer by applying fine geological research results, building a new driving system through selective perforating, organically combining flooding secondary oil recovery with tertiary oil recovery, strengthening flooding secondary oil recovery on a structural unit with remaining oil enriched in the thick oil layer, simultaneously performing proper comprehensive adjusting and then turning into the tertiary oil recovery at a proper time. According to verification, the oil deposit water-driving exploiting method of the ultra-high water-containing period achieves the aim of improving flooding exploitation effect, enhancing oil recovery and prolonging validity of flooding exploitation, and can guide the exploitation and adjustment of the ultra-high water-containing period of the oil field.

The invention relates to the technical field of oil-field development, in particular to a calculation method for water saturation of a water flooded layer of an ultralow permeability reservoir. The method includes: acquiring water flooding degree of the reservoir; establishing a first relation between cementation factors in rock-electro parameters of the water flooded layer and porous structure parameters as well as a second relation between saturation exponent and the porous structure parameters; solving resistivity of mixed fluid of the water flooded layer; calculating the water saturation of the water flooded layer to be evaluated by the aid of the first relation, the second relation and the resistivity of the mixed fluid. By the method, the water saturation of the water flooded layer, specifically the water flooded layer of the ultralow permeability reservoir can be obtained more accurately, and the water flooded layer can be evaluated more accurately under the background of highly mineralized formation brines.

The invention relates to the technical field of well logging and discloses a water flooded layer well logging evaluation method and system. Sample values of at least two water flooding strength evaluation indexes of the same water flooded layer in a same petroleum well are acquired, weight analysis is performed on the sample values of the water flooding strength evaluation indexes, the weights of the water flooding strength evaluation indexes are acquired, according to the weights of the water flooding strength evaluation indexes, the sample values of the water flooding strength evaluation indexes are subjected to weighing calculation to obtain water flooding indexes of the water flooded layer, and thus the water flooding strength of the water flooded layer in the petroleum well is determined, and the accuracy of well logging evaluation of the water flooded layer is improved. Errors caused by a single-factor evaluation method are avoided.

The invention discloses a method for water-flooding abandoned condensate gas reservoirs. The method includes performing full fluid PVT (pressure-volume-temperature) analysis first to complete long-core displacement experimental analysis. The long-core displacement experiment mainly includes the steps: selecting core samples on site; testing basic physical-property parameters of cores; splicing the core samples into a long core for displacement experiment, performing natural energy failure experiment, performing displacement in flooding, acquiring recovery rate of water-displacing condensate oil and condensate gas under different conditions according to the experiments, and comparing to determine the waterflood pattern which is most satisfactory to the requirement of increasing recovery rate of condensate gas reservoirs on site; and compiling a condensate gas reservoir water-flooding scheme according to indoor experiment results. The problem that existing depletion development of condensate oil-gas reservoirs is fast in energy decline, causes underground condensate oil loss and is low in production level is solved. Reasonable water-flooding speeds and water-flooding modes are optimally selected by the method and used for water flooding of abandoned condensate gas reservoirs, so that recovery rate of condensate oil-gas reservoirs is effectively increased.

The invention relates to an oil field water flooding classification well group development effect benchmarking method which comprises the following specific steps: (I) performing single well classification of an oil production well and a water injection well in an oil field block, and calculating a well group single-layer classification evaluation value; (II) establishing a calculation formula ofa water injection rate dividing coefficient of the water injection well, and calculating the water injection rate dividing coefficient of the water injection well; (III) correcting the water injectionrate dividing coefficient of the water injection well; (IV) acquiring the current-month accumulated effective water injection rate of the oil production well 1 in the well group, and establishing a relation curve between the current-month accumulated effective water injection rate of the well group and the current-month recovery percentage of the oil production well 1; (V) performing single wellgroup clustering in the class I, class II or class III well group by use of the Frechet distance algorithm and the relation curve between the accumulated effective water injection rate of the well group and the recovery percentage, to obtain a standard curve of recovery percentage of the well group; and (VI) based on the recovery percentage benchmarking curve data of three types of well groups, finding a single well group below the data of the three benchmarking curves, and performing development adjustment. The method provided by the invention is used for guiding the development work in the same type of blocks.

The invention provides a dynamic analyzing method for shallow ultra-low permeability sandstone reservoir water-filling development. The method comprises: normalizing all oil-and-water relative permeability curves of an oilfield development horizon to obtain an oil-and-water relative permeability curve that could represent an entire oilfield; through the use of the oil-and-water relative permeability curve, obtaining a B-type waterflooding characteristic curve; using the accumulated oil production amount and the accumulated water amount of the previous exploitation periods to predict the waterflooding geological reserves; based on the waterflooding characteristic curve and according to the accumulated oil production amount, the accumulated water amount and the waterflooding geological reserves, predicting the exploitable reserves and the exploitation rate; based on an indoors started pressure gradient experiment, fitting the relationship of the started pressure gradients under different permeability rates; and using the waterflooding characteristic curve coefficients, the accumulated oil production amount coefficients, the accumulated oil production amount, and the started pressure gradients to predict the future dynamic state of an oil reservoir. According to the invention, oil-and-water relative permeability curves are used to calculate the waterflooding characteristic curve in combination with the influence of the started pressure gradients on the parameters, making the method suitable for the dynamic analyzing of shallow ultra-low permeability sandstone reservoir water-filling development.

The invention discloses a cement-formation interface maintenance and cementation quality evaluation device and method under formation water disturbance. The device comprises a kettle body, an injection pump, an annular pressure pump, a pressure pump and a heating control device, wherein a rubber jacket and a ring-shaped rock core are arranged inside the kettle body, an upper sealing head and a lower sealing head seal the two ends of the kettle body, a leather bag is fixed in the internal cylinder of the upper sealing head and used for simulating pressure of the upper part of cement paste, a shallow groove is formed in the center of the lower sealing head, a gasket is arranged in the lower sealing head, a water inlet and a water outlet are formed in the side surface of the kettle body, formation water enters the rock core through the water inlet by virtue of the injection pump and flows out by virtue of the water outlet, and flowing of the formation water in the ring-shaped rock core isrealized. The device disclosed by the invention can simulate an underground high temperature environment, an annular mud cake is formed on the inner wall of the ring-shaped rock core, interference and destruction of disturbance of the formation water in a high water-cut period during later period of oil field water flooding development are studied, influence of annular pressure difference on cement-formation interface cementation quality also can be studied, and shear strength and hydraulic cementation strength of a cement-formation interface can be determined accurately.

The invention provides a complicated fault block oil reservoir development well pattern optimizing design method which is based on complicated fault block target area fine geology research and reasonable development layer division. Firstly, structural forms are performed, individual layer blocks are finely classified, the classification is performed according to the oil-bearing area size, then main geologic features and main development characteristics of the similar oil reservoirs are abstracted, and characteristic models of classified and graded complicated fault block oil reservoirs are established. Reasonable well spacing density, injection-production well pattern and injection-production parameter design optimization is carried out through a mathematic and numerical simulation means. Reasonable injection-production well pattern and production parameters of a series of classified and graded complicated fault block oil reservoirs are obtained, and well pattern optimization design of the complicated fault blocks is finished. By adopting the complicated fault block oil reservoir development well pattern optimizing design method, reasonable injection-production well pattern of the complicated fault block oil reservoirs with respective different structural forms in different areas can be quickly confirmed, the reserve utilization and water flooding control degree of the complicated fault block oil reservoirs can be improved, and efficient development of the fault blocks can be achieved.

The invention relates to a polyacrylamide reversed-phase microemulsion profile control system, and mainly solves the problems in the prior art that a polymer microballon subjected to profile control is easily broken through by water flooding and is bad in expansion property at a high temperature and a high salinity. The polyacrylamide reversed-phase microemulsion profile control system is prepared from a reversed-phase microemulsion under the effect of an oxidation reduction composite initiator through a polymerization reaction. The reversed-phase microemulsion comprises, in parts by weight, 1) 10-70 parts of an oily solvent, 2) 1-25 parts of an emulsifier, 3) 0.01-15 parts of a hydrophobic monomer, 4) 5-60 parts of acrylamide, 5) 1-40 parts of a water-soluble temperature-resistant salt-resistant monomer, 6) 0.001-5 parts of a cross-linking agent, and 7) 10-60 parts of water. The technical scheme relatively well solves the problems and applicable to tertiary oil recovery.

The invention provides a staggered well arranging method for ultra-low permeability tight oil reservoir volume fracturing horizontal well quasi-natural energy exploitation. The method comprises the steps of 1) firstly carrying out comprehensive geological research, selecting a horizontal well network deployment area preferably, carrying out reservoir classification evaluation, and determining a main contribution interval; 2) optimizing the horizontal segment length; 3) optimizing the well spacing; 4) optimizing the segment distance between fracturing fractures; 5) determining the array distance. The method can utilize the natural energy oil drainage function of horizontal well volume fracturing fracture networks to the greatest degree and avoids the risk of water breakthrough in water flooding exploitation; volume fracturing retention fluid achieves the effects of replenishing energy at an early stage.