Zhongxi is a complete laboratory for analysis and testing, also an audited contract laboratory.We can provide a wide range of chemical analysis and material testing services to a diverse international customer base.Our expertise and years of experience enable us to choose the right analytical methods and generate the accurate data needed to solve your toughest problems.
Detection range
Paraffin base crude oil, naphthenic base crude oil, intermediate base crude oil, ultra low sulfur crude oil, low sulfur crude oil, sour crude oil, high sulfur crude oil, light crude oil, medium crude oil, heavy crude oil, naphtha,colloid,asphaltene,sludge,etc.
The test items
Color, density, viscosity, freezing point, solubility, calorific value, fluorescence, optical rotation, impurity content, wax content, sulfur content, gum content, alkanes, cycloalkanes, aromatic hydrocarbons, etc.
Analyze project
Carbon element detection, hydrogen element detection, sulfur element detection, hydrogen sulfide detection, sulfide detection, disulfide detection, elemental sulfur detection, nitrogen element detection, oxygen element detection, etc.
Metal element detection: nickel element detection, iron element detection, vanadium element detection, copper element detection, arsenic element detection, etc.
Crude oil salt detection: sodium chloride detection, magnesium chloride detection, calcium chloride detection, etc.
Experiment flow
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Introduction to some experiments:
Test of Core permeability
Detection device :
Gas permeability Equipment
The permeability of reservoir rock is the main mark of evaluating reservoir quality.
The method of core permeability measurement in our laboratory is direct method: to get gas through the core,after the flow state of gas through the core is stable,measure the inlet and outlet pressures P1 and P2 at both ends of the core and the corresponding flow rate Q under this pressure difference, the viscosity of the gas flowing through the core is obtained from the standard,core permeability calculated by Darcy-Weisbach Formula.
Porosity test
Test parameters: fluid porosity,air porosity,helium porosity,(test the porosity of different media according to user's requirement).
Saturation test
Testing equipment:oil-water saturation measuring apparatus(cracking process).
Mercury injection experiment
Mercury injection method is also called mercury porosity method,it is a method to determine the pore size distribution of partial mesopore and macropore.
Basic principles:Mercury does not moisten ordinary solids,to get mercury into the hole, an external pressure is applied,the greater the external pressure, the smaller the radius of the hole into which mercury can enter.The pore volume of corresponding pore size can be obtained by measuring the amount of mercury entering the pore under different external pressures.The pressure of mercury injection instrument used at present is about 200MPa at most,measurable hole range:0.003 - >1000μm(hole diameter).
In the physical simulation test of reservoir,used to plot capillary pressure curves,can be used to describe the characteristics of multiple reservoirs,In particular, the pore roar size distribution of porous media,in particular, the pore roar size distribution of porous media.
Mercury is injected with a very low injection rate through a high precision injection pump,a system for automatically determining the results of microscopic pore structures.The system includes a specially designed precision injection pump with an extremely low rate and a core holder integrated with it, as well as a high-precision pressure sensor.
Technical characteristics of mercury injection apparatu:
1.Pore size range:0.003 to 1000 µm;
2.There is no less than one low voltage station and high voltage station,to meet the test of a variety of samples of high - level security protection,it can be safely used even under high pressure and toxic mercury environment;
3.Low noise,high pressure system;
4.Scan mode or rate balance mode can be operated;
5.Collect very high resolution data;the volume accuracy of mercury input or withdrawal is better than 0.1μL;
6.Closed mercury system(With mercury content is low).
Core cast sheet：
Testing equipment: Rock pore casting instrument, slice cutting machine.
Main parameters: the content, type and distribution of pores were studied.
Thin sheet technology is one of the three conventional technologies for lithofacies analysis and gas reservoirs and is also the most basic one.Using optical microscope to observe the thin slice, the information obtained from the thin slice of cast is more reliable.A sample made of a thin cast is best formed in the core.Sheet thickness 0.03 mm, area not less than 15×15 mm.With the exception of no coring, use less or no chips,because rocks tend to rupture along weak junctions, dense cemented rock blocks can remain large in size, which leads to a understanding of pore development and cementation.
Main uses and features:
1.Suitable for pore structure research, such as face rate, pore size, connectivity;
2.Rock type, structure and microstructure can be observed;
3.The iron content of carbonate minerals can be given by mineral dyeing;
4.Study the origin of minerals, crystal order.
Reservoir sensitivity test
Detection device：Core displacement equipment
According to Darcy-Weisbach Formula,inject various fluids related to formation damage under the conditions set in the experiment,or changing seepage conditions (flow velocity, net confining pressure, etc.),determination of permeability and its change of rock sample,in order to judge the critical parameters and evaluate the damage degree of rock permeability caused by the change of experimental liquid and seepage conditions.
Detection classification:stress sensitivity;flow velocity sensitivity;salinity sensitivity,water sensitivity, acid sensitivity and alkali sensitivity
1.Stress sensitivity refers to the phenomenon that when the net overburden pressure changes, the pore throat channel is deformed, the fracture is closed or opened, resulting in the change of reservoir rock permeability.
2.Flow velocity sensitivity refers to the phenomenon that due to the change of fluid flow velocity, the particle migration in reservoir rock can block the throat and lead to the change of reservoir rock permeability.
3.Salinity sensitivity refers to a series of salt water with different salinity after entering the reservoir, because of the change of fluid mineralization degree, the clay mineral expands or disperses and moves, which leads to the change of reservoir rock permeability.
4.Water sensitivity refers to the phenomenon that the injected water with lower mineralization degree causes the clay to expand, disperse and move after entering the reservoir, which makes the seepage passage change and leads to the change of reservoir rock permeability.
5.Acid sensitivity refers to the phenomenon that acid and liquid react with reservoir minerals to produce precipitation or release particles, resulting in changes in reservoir rock permeability.
6.Alkali sensitivity refers to the phenomenon that alkaline liquid reacts with reservoir minerals to produce precipitation or cause clay dispersion and migration, resulting in changes in reservoir rock permeability.
Available:Critical flow velocity, critical salinity,critical stress, critical pH,etc.
The laboratory adopts advanced ISCO displacement pump to carry on the displacement experiment, the accuracy can reach 0.00001 ml/min.
It has been proved that particle migration can occur in all operations and is the most important of the possible causes of damage. It mainly depends on the size of the hydrodynamic force, the flow rate is too large or the pressure fluctuation is too large to cause the particle migration.
Evaluation of oil displacement efficiency and optimization of enhanced recovery proces
Criterion of detection: High temperature and high pressure long core displacement equipment.
Test items: Test of oil displacement efficiency under reservoir conditions, such as water flooding, gas flooding, chemical flooding, etc, evaluation of oil displacement effect and optimization of displacement medium and process under different displacement medium and oil recovery process conditions.
High temperature and high pressure long core displacement experimen
Criterion of detection: High temperature and high pressure long core displacement equipment.
The long core displacement experiment is to replace the original standard core with relatively long core, with good representativeness.
Through the long core displacement experiment, the injection method of low permeability oil and gas field is evaluated and optimized, which provides a basis for the development of low permeability oil field.
The long rock core displacement experimental setup used takes into account the need of similar conditions for core length, as well as the stage and mechanism complexity of the physical and chemical processes of multiple contact blends.The device can perform a variety of displacement experiments under reservoir conditions, these experiments include: Secondary oil recovery experiment with water or gas flooding, use injection of solvents (such as nitrogen, hydrocarbons, carbon dioxide, etc.) or injection of polymer, the dynamic laboratory simulation of eor was carried out with colloidal dispersion gels and other chemical oil displacement agents.The core length of the device is 2m, and its working pressure and temperature are 60MPa and 150℃ respectively.The carbon dioxide injection displacement experiment can be successfully carried out by using the experimental device, get oi reservoir fluid to water, pressure during alternating carbon dioxide flooding, important parameters such as yield and phase state change.
Gas porosity and permeability analysis of overburden cor
Criterion of detection: High temperature overburden porosity and permeability tester.
Test parameters: Length and diameter of rock samples, porosity, pore volume, gas permeability, kirschner permeability (i.e. equivalent liquid permeability), etc.
Overburden porosity and permeability is the effect of overburden on porosity and permeability of reservoir.
Based on gas darcy's law and gas isothermal variation (i.e. Booma's law), the overburden pressure porosity and permeability testing system adopts core to be tested to test the core permeability by comparing the core to the benchmark, and the core series method, and obtains the core porosity by using high-precision pressure sensors to measure the diffusion pressure.
The non-steady pressure pulse attenuation method is used to measure the pressure and measure the flow rate with higher accuracy. the flow calculated by the pressure pulse attenuation measurement is more accurate, especially suitable for low permeability samples that do not obey darcy's law. Rock gas phase permeability and porosity can be measured under real reservoir pressure conditions.
High pressure physical property analysis of formation flui
Criterion of detection: Mercury-free high pressure physical property analyzer, Sample matching machine, sample changer, chromatograph.
Stratigraphic fluid refers to oil, gas, water and so on which exist in the rock pores of reservoir.
High pressure physical property parameters of formation fluid refer to the physical property parameters of oil and gas flow body under formation conditions.
Oil gas reservoir formation fluid high pressure physical property parameters are important basic data to support reservoir engineering design. Oil gas the accuracy of high pressure physical parameters of reservoir fluid will directly affect the reliability and rationality of reservoir type classification, characterization, reserve calculation and development mode selection.
The experimental process generally includes: Sample inspection, formation fluid preparation, turn to the sample, thermal expansion tests, single degassing experiment, constant mass expansion experiment, multiple degassing experiments，constant volume depletion experiment, formation oil viscosity test, etc.
Different PVT test items are selected according to different composition of formation fluid.
Starting pressur
Criterion of detection: At present, there is no fixed, unified and perfect research method, and there is no unified and perfect research method guidance.Generally there are: mathematical calculation, laboratory experiment, numerical modeling, IPR and well test interpretation five species.
Testing equipment: High temperature and high pressure core displacement equipment.
Low permeability reservoir due to fine pore throat,in the process of seepage, the fluid is strongly affected by the surface molecular force on the interface between the rock pore wall and the fluid solid liquid, so a starting pressure difference is needed to get the fluid flowing.The minimum pressure to start the flow of fluid in a low permeable reservoir is called the starting pressure,the minimum pressure to start the flow of fluid in a low permeable reservoir is called the starting pressure.
The flow characteristics and mechanism of fluid in porous media are influenced and controlled by factors such as fluid properties, porous media properties and the interaction between them.The pore medium of low permeability reservoir is mostly microscale, as the flow characteristic scale decreases, will produce a scale effect different from the traditional flow law. The scale effect of porous media flow space complicates the flow of fluid in it, nonlinear seepage law, starting pressure gradient and variability of flow section exist,therefore, there are non-Dasi seepage phenomena in high permeability reservoirs, low permeability reservoirs and non-Newtonian non-Newtonian fluids such as heavy oil and polymer, including nonlinear seepage and starting pressure gradient characteristics. The existence of starting pressure gradient will affect the water injection pressure limit of low permeability oil field and the size of well spacing of development well network, at the same time, it also has influence on the development index of oil field, so it is very important to study the starting pressure gradient systematically for the efficient development of low permeability oil field.
High temperature and pressure oil-water relative permeabilit
Testing equipment: High temperature and high pressure core displacement equipment.
The relative permeability of a fluid is the ratio of the effective permeability to the absolute permeability of the fluid, it is a direct measure of the ability of a fluid to pass through rock.
The "unsteady-state method" is based on the one-dimensional two-phase water-driven leading edge propulsion theory. Ignoring capillary pressure and gravity, it is assumed that the two-phase insoluble fluid is incompressible, and the oil-water saturation is uniform in any cross section of the rock sample.The experiment is not to inject two fluids into the core at the same time, but to saturate the core in advance with one fluid and drive the core with another fluid.In the process of water flooding, the distribution of oil-water saturation in porous media is a function of distance and time is a function of distance and time, which is called unstable process.According to the requirements of the simulation conditions,perform constant pressure differential or constant velocity water displacement experiments on reservoir rock samples, record the yield of each fluid at the outlet of the sample and the variation of pressure difference at both ends of the sample over time, then calculate the relative permeability of oil - water, the relation curves between oil-water relative permeability and water saturation are also drawn.
The laboratory mainly aims at the experimental design of oil-water phase permeability of ultra-low permeability core,automatic data recording,with data analysis software,fully automated,the long experimental process of low permeability core is solved.
Evaluation and optimization of fluid damage in well
Checkout equipment:High temperature and high pressure core displacement system.
Test items:Drilling fluid, fracturing fluid, perforating fluid,Damage rate of reservoir permeability of kill fluid,evaluation of reservoir protection performance, material and formula selection of different well entry fluids.
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