136 results about "Fracture conductivity" patented technology

A well treating composition contains an aqueous acid and at least one relatively lightweight proppant, preferably having an apparent specific gravity (ASG) less than or equal to 2.45. The acid fracturing composition may used to acid fracture a hydrocarbon reservoir within a subterranean formation of an oil or gas well. The composition may further be used to stimulate the production of hydrocarbons. The proportion of relatively lightweight proppant to acid in the composition is such that the dimensional fracture conductivity (C_fD) is in excess of 1.0. The aqueous acid typically has an ASG substantially equal to the ASG of the relatively lightweight particulate. As such, the relatively lightweight particulate is suspended in the aqueous acid.

A method for forecasting performance for and characterizing the properties of a multilayer low permeability gas reservoir. The method includes a coupled well/reservoir predictive model that accounts for pressure drop between layers, allowing accurate, rigorous, and rapid forecasting of reservoir performance. The method provides estimates of individual layer properties such as in-situ permeability, skin factor, fracture half-length, fracture conductivity, drainage area, etc. by simultaneously history matching production data and production log data using the coupled well/reservoir predictive model.

Embodiments of hydraulic fracturing methods disclosed herein use fine mesh proppant. In one embodiment the method is used to fracture a low permeability formation. In one embodiment the method uses flocculation to improve conductivity of a fracture. In one embodiment fluid flow through the fine mesh proppant in the fracture creates a network of connected channels to improve the fracture conductivity.

Lightweight polyamide particulates may be used in treatment of subterranean formations, including hydraulic fracturing and sand control methods, such as gravel packing. The polyamide particulates typically have an apparent specific gravity (ASG) between from about 1.05 to about 2.0 and are stable at temperatures up to 500° C. The polyamide particulates may be used in combination with a filler which further serves to increase the strength and temperature stability of the resulting composite. Fracture conductivity may be increased by the placement of the low density polyamide particulates as a partial monolayer.

The invention relates to fracturing reformation in the field of oil-gas field development, in particular to a method for optimizing fracture conductivity of a tight gas-reservoir fractured horizontal well. The method mainly comprises the following steps of (1) collecting basic parameters of a reservoir, fluid property and a horizontal well shaft; (2) collecting basic parameters of fractures of the fractured horizontal well; (3) evenly dividing each fracture of the fractured horizontal well into line congruence with equal length along the fracture length direction; (4) building a reservoir permeability model for a tight gas-reservoir fractured horizontal well fracture system; (5) building a flowing decompression model of gas in the fractures; (6) building a flowing model of coupled gas in the reservoir permeability and the fractures, and forming a yield calculation model of the tight gas-reservoir fractured horizontal well; (7) optimizing the fracture conductivity of the tight gas reservoir fractured horizontal well. By utilization of the method for optimizing the fracture conductivity of the tight gas-reservoir fractured horizontal well provided by the invention, the shortages of the prior art can be conquered, and the problem of optimizing non-constant fracture conductivity of the fractured horizontal well along the fracture length direction is effectively solved, so that reasonable basis is provided for the optimization design of reservoir reformation, and the reservoir reformation effect is improved.

The method disclosed herein includes the introduction of proppant-free stage and a proppant laden stage into the wellbore and/or subterranean formation. The method increases the effective fracture width and enhances fracture conductivity within the formation. Either the proppant-free stage or the proppant laden stage contains a breaker. The other stage contains a viscosifying polymer or viscoelastic surfactant to which the breaker has affinity. The proppant-free stage may be introduced prior to introduction of the proppant laden stage into the wellbore and/or formation. Alternatively, the proppant laden stage may be introduced into the wellbore and/or formation prior to introduction of the proppant-free stage.

The invention discloses a method for experimentally determining carbonate rock oil and gas reservoir acid fracturing fracture conductivity distribution. The method comprises the steps that an acid fracturing simulator FracproPT is adopted for simulating the down-hole acid fracturing fracture extending and acid etching process during acid fracturing, and fracture width distribution, fracture height distribution, temperature distribution and acid liquor mass concentration distribution data in the hydraulic fracture length direction are obtained; in the hydraulic fracture length direction, fracture width, fracture height and temperature data of total 10 feature points with the acid liquor mass concentration being 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10% of the initial mass concentration are selected; acid injection displacement of the oil field site scale is converted into acid injection displacement of the laboratory scale; according to the acid liquor mass concentration data of the 10 feature points, acid liquor used for an experiment is prepared; and the acid etching process is simulated, the conductivity under the condition of reservoir closed pressure is tested experimentally, and a distribution diagram of the acid etching fracture conductivity in the fracture length direction under the reservoir condition is drawn. The method is reliable in principle and simple and convenient to operate and has wide market prospects.

Methods of treating a subterranean formation having at least one fracture including providing a cement slurry comprising an expandable cementitious material and a breakable foamed carrier fluid, wherein the expandable cementitious material is capable of consolidating to form a plurality of expandable cementitious material aggregates and wherein the breakable foamed carrier fluid is capable of coating and isolating the expandable cementitious material aggregates; introducing the cement slurry into the fracture; curing the expandable cementitious material aggregates so as to form a cement pillar within the fracture in the subterranean formation, wherein the curing of the expandable cementitious material aggregates expands the expandable cementitious material aggregates such that at least one microfracture is created within the fracture; breaking the breakable foamed carrier fluid; removing the broken breakable foamed carrier fluid from the subterranean formation; and acid-fracturing the at least one fracture in the subterranean formation.

The invention provides a shale gas reservoir complex fracture conductivity simulation experiment method. The method comprises the following steps that (a) a stratum shale core or a peer position shale outcrop for manufacturing a test piece is selected, and shale materials are processed into a shale slab, wherein the length of the shale slab is 17.7 cm, the thickness of the shale slab is 1.5 cm, the width of the shale slab is 3.8 cm, and the two ends of the shale slab are in a semicircular shape; (b) the shale slab is further processed to meet the requirement of turning fractures or branch fractures; (c) the processed shale slab is put in a conducting room for testing the fracture conductivity, and a propping agent with the certain sanding concentration is laid in the middle of the shale slab; (d) the conducting room with the propping agent and the shale slab well arranged is put in a fracture conductivity testing device to conduct a conductivity experiment test. For fractured fragile shale with complex fractures, the shale gas reservoir complex fracture conductivity simulation experiment method can be used for studying the conductivity of the turning fractures and the branch fractures formed through fracturing of shale gas reservoirs and evaluating the influence on the fracture conductivity by the fracture steering degree and the branch fracture form.

The invention discloses a method for evaluating the volume transformation capacity of a vertical well of a fractured tight oil reservoir. The method comprises the following steps: forming a transformation fracture network near a well bore, wherein the transformation region is divided into two parts, namely an inner area and an outer area, the inner area is an artificial main fracture transformation region, and the flow conductivity of an artificial main fracture is much higher than external supply, so that the region is assumed to have limited artificial main factures during a model derivation process, the attribute parameters of all factures are consistent, and the seepage of the fluid in a main fracture is linear seepage and follows the Darcy law; under the combined action of artificial fracture extending and reservoir rock brittle shear, the artificial fractures, shear fractures and natural fractures are criss-cross, so that the seepage mode of the region is changed into fracture conductivity primarily; a semi-analytical two-region comprehensive mathematical model which can be used for evaluating the volume transformation capacity of the vertical well is established. The method is applicable to evaluating multi-fracturing of the vertical well of a closed boundary fractured reservoir and the volume transformation of the vertical well of the fractured tight oil reservoir; reference is provided for reasonable development of the tight oil reservoir.

Belonging to the technical field of oil and gas exploitation, the invention provides a fractured shale gas-water two-phase flow fracture conductivity evaluation device and method. The device consistsof a seepage system, an injection system, a data acquisition and processing system and a triaxial core holder. Specifically, the seepage system is divided into a water injection stage and a gas flooding stage. The method includes: firstly using the device to determine the initial permeability and initial mass of a shale sample; conducting water injection to the shale sample for water invasion experiment and ending water injection when core effluent water flow becomes stable; adding a dryer, then conducting gas flooding on the shale sample, collecting the gas flooding zone outflow water phase fracturing fluid, and ending gas flooding until a flowmeter measures stable gas output. The device and method provided by the invention measure that the permeability of the shale sample at the water injection stage and gas flooding stage varies with time, and explore the influence of water phase fracturing fluid invasion on shale fracture conductivity and the seepage law. The device and method canaccurately determine the seepage law of shale gas in microfractures, and the operation is simple.

The invention discloses a rock fracture simulation sample and a preparation method thereof, as well as a simulation test device and a simulation test method and belongs to the technical field of rock simulation tests. The simulation sample comprises a body and a fracturing fluid injection pipe, wherein a blind hole is formed by taking one end surface of the body as a start point; the fracturing fluid injection pipe is fixedly connected with the wall of the blind hole; an accommodating space is reserved between the bottommost end of the fracturing fluid injection pipe and the bottommost end of the blind hole. The simulation sample can be prepared by the preparation method. The simulation test device comprises a triaxial test apparatus, wherein the triaxial test apparatus comprises a triaxial chamber, an upper pressing head, a lower pressing head, a confining pressure oil injection mechanism, a fracturing liquid injection pump and the rock fracture simulation sample. The simulation test method is realized on the basis of the simulation test device. According to the simulation test method, vivid complex fracture seams can be formed in a rock sample, and a fracture conductivity test is performed on the basis of the fracture seams, so that the obtained rock gas pool deliverability evaluation is relatively approximate to actual evaluation data, so as to guide actual work more objectively.

Methods of treating a subterranean formation including providing a wellbore in a subterranean formation having at least one fracture; providing an expandable cementitious material; introducing the expandable cementitious material into the at least one fracture in the subterranean formation; curing the expandable cementitious material so as to form a cement pack, wherein the curing of the expandable cementitious material expands the expandable cementitious material such that at least one microfracture is created within the at least one fracture in the subterranean formation; and acid-fracturing the at least one fracture in the subterranean formation.

Methods of treating a wellbore in a subterranean formation having a top portion and a bottom portion, and a middle portion therebetween. The method includes providing a jetting fluid; providing a cement slurry; and providing a breakable gel fluid. Then introducing the jetting fluid into the bottom portion of the wellbore to create or enhance a bottom portion fracture; introducing the jetting fluid into the top portion of the wellbore to create or enhance a top portion fracture; introducing the cement slurry into the top portion fracture; introducing the cement slurry into the bottom portion fracture; and introducing the breakable gel fluid into the wellbore so as to prevent the expandable cementitious material from migrating out of the top portion fracture and bottom portion fracture. The expandable cementitious material is cured so as to form a cement pack, the breakable gel fluid is broken and removed from the subterranean formation.

The invention provides an energy complementing and fracturing stimulation integrated repeated transformation method of a dense oil reservoir old well. The method comprises the following steps: S1, analyzing according to an early stage reservoir scaling type, using an optimized blockage relieving fluid formula to squeeze small-displacement blockage relieving fluid into an old well original perforation interval, removing formation wax and inorganic scale; S2, according to reservoir refracturing static pressure requirement, injecting a low-viscosity oil displacement fracturing fluid in medium displacement to an objective interval; S3, in an injection last phase of the objective interval, performing volume fracturing repeated transformation construction with low sand proportion, large displacement, and low-viscosity fluid as a main method, to further expand reservoir transformation volume and recover main fracture conductivity near a shaft; S4, after construction of the objective interval, shutting the well in to diffuse pressure, until wellhead pressure is reduced to 0MPa; S5, removing sand to complete the well, and putting the well into production . For a reservoir which is insufficient in initial stage transformation or an oil well whose fracture conductivity reduces obviously, the method further expands reservoir transformation volume, and realizes objectives of oil well production enhancement and natural decline reduction.

The invention discloses a proppant embedment and fracture conductivity quantitative forecast-based numerical simulation method. The method comprises the following steps of: S1, establishing a physical model for reducing the real sizes of proppants; S2, applying closing pressure on the surfaces of an upper rock stratum and a lower rock stratum of the model, wherein the difference between average heights of granules on fracture surfaces of the upper rock stratum and the lower rock stratum is a fracture closing width w; S3, carrying out flow field grid dispersion on a filling layer to ensure that a flow field is wrapped by the proppants, setting viscosity and density of a fluid and pressure of the fluid at two ends of the flow field; S4, calculating a total flow q of the flow field; S5, calculating a permeability and a flow conductivity; and S6, changing physical parameters of the rock stratums or the fluid, and drawing a change curve graph indicating that the conductivity of the proppants with different sanding concentrations changes along with closing stress. The method has the beneficial effects of simulating the real processes of fracture closing, proppant embedment and interaction between granules and fluids, so as to effectively forecast the dynamic change of the flow conductivity.

The invention relates to a pressure control injection yield increase method for a coalbed methane well. The radius affected by the pressure of a created fracture after thehydraulic fracture according to the gas production rate, the coal seam thickness and the gas content per ton after the fracture of the coal petrography; the injection solution amount for yield increase is determined; a sleeve can be injected when the sand wash of the borehole operation is 10m far from a coal seam; two bottles of fracturing fluids are connected into an inlet of a plunger pump in parallel; the outlet of the plunger pump is connected with a sleeve valve of a gas collection tree, and a well mouth is provided with a pressure meter; and the accumulated water yield during the production period of a construction well is injected into the coal seam with the maximum pump discharge for filling the volume of the recover part, fluids can be injected by controlling the pressure, 5-20 Mpa injection amount of the fluids is injected in small pump discharge and steady pressure ways according to different pressures, the injection can be stopped when the stratum is saturated and the fluids can not be injected. The well mouth is pressure free in 3-5 days; and when the stratum is saturated and the pressure is not decreased to 5Mpa during the fifth-seventh day, the construction of the well can be finished. The invention has the beneficial effects that the method is suitable for the growth feature of the coal petrography of high order coal, the fracture conductivity is improved, and the generation of coal dust can be controlled.