Ultrasonic technology of intensification of oil and gas condensate recovery

An ultrasonic software and hardware system for intensification of oil recovery consists of a powerful ultrasonic transducer, software and ultrasonic emitters, powered through a standard 3 core logging cable.

The whole equipment, realizing the acoustic stimulation technology, is compatible with regular equipment of geophysical parties which does not cause any difficulty of learning by regular geophysical personnel.

The acoustic stimulation technology consists in processing of collector formations (in an open bore, in a filter or perforated holes interval) by a powerful ultrasonic field aimed at renovation of their filtering properties.

The processing is carried out point by point (with 0.5-1.0 m interval) selectively based on the “inflow profile-stimulation profile” principle.

Well and equipment preparation is practically the same as that for standard geophysical researches.

The integrity of an operational column and cement stone over is ensured and the process of stimulation is technically and physiologically safe and environmentally sound .

We can say without exaggeration that nowadays the acoustic stimulation of oil wells (in ultrasonic version) is a modern, hi-tech, reagent-free geophysical method of controlled and selective influence on a formation and bottomhole zone for intensification of inflows and oil recovery increase, applicable in a wide range of geological-technological conditions, with rather long (till 2 years and more) and essential (often multiple) effect, besides it is almost faultless for a formation and an oil well and is ecologically pure, and also is easily combined with other known methods of intensification and increase of oil recovery.

This technology allows, without any damage to oil-bearing sand, to achieve effectively restoration of filtration properties of productive layers at minimum time and material costs.

Application of ultrasonic and information technology in oil and gas engineering

Equipment for processing of operational and pressure wells to increase their efficiency ( throttle response ) and increase of oil recovery.

Equipment for processing of filters, oil well tubes, pumps and other equipment for preventing (maintenance prevention and liquidation) of paraffin formation and other asphalt-resinous paraffin sediments.

Equipment for processing of commercial sites and main pipelines, process vessels etc. with the purpose of the change of rheological properties of oils and petroleum products (decrease in viscosity etc.)

Equipment for processing of welded joints to relieve residual stresses and extension of service life of welded structures (tankers, pipes, oil platforms etc.).

Development of software for numerical modeling of an oil formation.

Competitive advantages of complex approach of ultrasonic treatment

Technology Features	Brief Description
Reagent-Free	No need for expensive chemicals (acids, solvents, surfactants, etc.)
Selectivity	Selectivity of influence on particular phases of a multiphase environment and selectivity of extraction of useful components.
Controllability	Operative controllability of time and intensity of influence, speed of processes, etc. on the basis of a feedback.
Indestructibility	Indestructible structures of environment and “renewability” of influences with initial parameters.
Manufacturability	Small quantity of operations, computerization etc.
Ease	Flexibility, mobility and fine tuning of technology
Combinability	Possibility of simultaneous (parallel) influence on different phases, including a combined one with material methods.
Environment	“Defectless” (convertibility of “after effect”) for geological environment, low destructiveness for the environment, convenience of manufacturing.
Costs	Lower cost and labor intensive compared with all other methods and technologies.
Reduction of production cost	Numerical modeling allows to calculate a set of variants of oil production.
Increase of equipment service life	On the basis of virtual models of engines and pumps their exact selection is carried out
Energy efficiency	Selection of optimal operating modes of equipment
Increase of oil recovery from deposits	Complex and consistent approach to the development of a deposit on the basis of the presented technologies.

The plan of organizational-technical actions on oil and gas deposits during ultrasonic stimulation.

1. Preparatory organizational technical measures

Analysis of information submitted by the customer;

Selection of oil wells for acoustic stimulation, taking into account their technical-operational characteristics and dynamics of output change since the moment of their commissioning.

The information should include:

– well logging maps,

– inflow profile,

– permeability of interlayer,

– technical and operational indicators of the oil well,

– information about repair and technical operations for intensification of oil and gas production.

Development of plan of works on ultrasonic stimulation of an oil well and its coordination with executors.

Geophysical equipment includes a geophysical lift and a mobile geophysical laboratory, providing background thermometry, sweeping-up and binding of immersing , cabel-rope to a productive zone of layer.

Preparation of a geophysical lift and cable-rope with a small geophysical head (diameter of 38mm).

Parameters of KG-3 cable:

– running resistance of the strand R-12-15 the Ohm/km,

– Cable length – 3000-5000 m.

Equipment of a mobile geophysical laboratory with a network cable for mains system of 3 phases, 380 V, 50 Hz, (with consumption capacity up to 15 kW), a typical three-phase plug and automatic circuit breaker for the maximum current of 25 A

Preparation of measuring equipment for preparatory and control checks of the equipment of technological system of ultrasonic influence and measurements of parameters of a cable line. The measuring equipment includes: a setting generator, an oscilloscope, an alternating voltage voltmeter.

2. Preparatory works on a geophysicists site

Delivery of ultrasonic equipment to a geophysicist’s site. The typical structure of the equipment consists of one complete set of land generator and two types of acoustic emitter. The total weight of the equipment with a packing container is 50-75 kg.

Check of functioning of the ultrasonic equipment according to the instruction manual, connection of equipment with geophysical laboratory equipment and with geophysical lift cable.

Measurement of coefficients of transmission of the geophysical cable in a range of working frequencies. Check of limiting characteristics of the cable at the work of the transducer and an acoustic emitter through the cable to a load equivalent.

Preparation of the ultrasonic equipment and the special geophysical equipment to leave for working on oil wells.

Specification of the scope of works on concrete oil wells,

– time of ultrasonic stimulation,

– modes of radiation,

– number of stations and their arrangement in a productive zone.

Coordination of works with the leading geologist and customer supplying services, setting the time of the beginning and termination of ultrasonic stimulation.

3. Preparatory works on oil wells

Delivery of geophysical equipment to a work site on oil well.

Checking technical readiness of an oil well for ultrasonic stimulation, including possibilities for power supply, presence of lifting equipment.

Installation of a geophysical lift and geophysical laboratory, land generator, technological system of ultrasonic stimulation and measuring equipment.

Carrying out of geophysical measurements before ultrasonic stimulation, including:

– Background thermometry of a productive zone,

– Connecting equipment to a circuit of grounding and lining of cable connections.

– Connecting a network cable;

– Controlling of voltage of the power supply network;

– Connecting an ultrasonic transducer to the output of the geophysical cable;

– Checking of isolation resistance.

– Connecting an output cable of the generator to the geophysical lift collector,

Connecting power supply to the generator, switching on the equipment according to the manual.

Control of correctness of connection, control of impedance of loading and functioning of ultrasonic transducer.

Delivery of the ultrasonic equipment to the productive layer on the station.

Setting of parameters in radiation mode.

Registration of radiation parameters in a working archive (input pressure, input current, mode and frequency of radiation).

Carrying out of ultrasonic stimulation under the coordinated program.

Registration of radiation parameters for each workstation.

Completion of ultrasonic stimulation.

Lifting of ultrasonic transducer, control of functioning; switching-off power supply, dismantling of cables connections, preparation of the equipment for transportation.

Carrying out geophysical measurements after ultrasonic stimulation, including background thermometry in a productive zone of oil well.

End of work on the oil well.

4. Control over work of an oil well after the ultrasonic stimulation.

Analysis of geophysical measurements after the stimulation.

Estimation of power efficiency of stimulation.

Preliminary conclusion of productivity of ultrasonic stimulation for oil intensification.

Drawing up and coordination of the program of the subsequent supervision of the oil well.

Recommended periodicity of measurements: once a week during the first month and once a month during the rest of the year.

Working out, registration and coordination of a report of works on the oil well.

Equipment for ultrasonic stimulation of oil recovery

Progress-5000

Ultrasonic generator performance:

Supply voltage, V:	400х3
Pulse Power, W:	15000
Frequency, Hz:	15000-50000
Signal type:	Sinusoidal, modulated, pulsing
Automatic tuning in a wide frequency range
Oscillator sizes, mm:	699х933х616
Weight of the generator:	60 kg
geophysical cable length	up to 5000 m.

Recommended cable type: cable CG3х1,50-80-150

Designed for geophysical studies, blasting works in wells drilled for oil, gas, iron ore, coal and other minerals at the bottom hole temperature of 150° C and hydrostatic pressures up to 100 MPa.

Brief technical characteristics of the cable

Outer diameter	12,4 mm
Estimated weight	560 kg/km
Breaking Strength	90 kN
Maximum operating temperature of the bottom hole	up to 150°C
Hydrostatic pressure	up to 100 MPa
Conductor resistance	less than 25 Ohm/km
Insulation resistance	more than 20000 MOhm x km
Construction length	up to 5,0 km

The system operates in manual and automatic mode. It is equipped with a LED display and computer for input of operation factors and visual verification of operation of the oscillator. The oscillator is manufactured in a standard 19 “housing in tamper modification. All plug-and-sockets and operating controls are on the front desk of the oscillator. The oscillator is protected against line breakaways, short circuits, no-load operation. The oscillator is equipped with input voltage stabilizing. The oscillator ensures stabilizing of output parameters of current, stress and frequency. The complex is equipped with function of programmed cyclograms for operation in various conditions. The complex ensures record of operations. An automatic archiving in a computer memory of protocols of operations after formation treatment closing of the circuit is provided.

The Oscillator is compatible for operation with various types of geophysical cables and ultrasonic vibrators. Emitters are designed for operation under pressure up to 500 bar and temperature up to +125°С.

Characteristics of ultrasonic emitters:

Power of emitters	500 to 2500 W.
Dimensions of emitters:	Diameter 44 and 78 mm
Length	1250 to 2240 mm
Weight of emitters	5 to 25 kg

ultrasonic wave simulation
in a bench

modeling of
ultrasonic wave in a fracture

visualization of the process
of an ultrasonic transducer

Deployment of ultrasonic stimulation equipment of oil recovery

Узел подключения ультразвукового генератора к геофизическому кабелю

Геофизические иследования перед ультразвуковой обработкой (НКТ поднят)

Technology results

The collector is carbonate, porous-cavernous (mixed), D3 age (Fo layer), depth of 1789.4 – 1809.5 m, Tm-50°C, porosity – 9.2%. Oil: density (in superficial conditions) – 0.8769 g/cm3; in place conditions – 0.8421 g/cm3, dynamic viscosity of 7.29 mPa * s.

Comments:

This well is one of the first wells which was acoustically treated on 25.02.2007 on of the first in a series of our test treatments for ZAO Pechoraneft Company and it is a “Champion” with regard to the length of the post stimulation effect that lasts till present moment and is approaching 3 years (36 months ). At the same time the stable effect was attained with carbonate reservoir rocks, and stimulation expenses were paid off in 5 days after the stimulation (due to sales of additionally produced oil). Before the acoustic stimulation that well was known by a sharp oil rate decrease despite of the whole range of geological and technological measures.

This well is a “Record Holder” in a series of ultrasound treatments for ZAO Pechoraneftegaz with respect to improving flow rate indicator – 4.5 times (450%!). At the same time the well is known by high stability of operation (with some increase in the percentage of water content) with continued impressive effect for more than 2 years.

These results for 1142D well typical for a series of tests in Romania at marginal deposits are characterized by the fact that after the ultrasonic treatment the total flow rate of fluid has not changed, but the oil production rate increased by one and the half (1.5) times with a significant decrease in water content from 60% up to 30% (2 times).

Comments:

Optimization of the complex of accompanying geophysical research is extremely important for financial reasons, because the cost of these studies (binding depth and assessment of performance of the well “before” and “after” effects) are usually much higher than the actual value of the ultrasonic treatment. The represented here results of research were carried out by Weatherford company (USA) accompanied by our treatments in Romania, illustrate an adequate system for the rapid assessment of effectiveness of ultrasonic treatment and decision making. We are moving towards optimization of the set of methods and implementation of technical means and technologies for various conditions, as well as their autonomy (together with our downhole ultrasonic transducers).

Information and analytical preparation of works on an oil well (questionnaire)

Attention! This table is placed for familiarization, in order to obtain information about the appropriateness of the work on your well it is necessary to register and fill out a similar questionnaire in on-line.

Name of the well
Well location
Date of drilling/production stops
If the production is stopped - for what period or permanently
Status
Type of the well
Altitude (rotary table)	m
Casing length	m
Inner diameter of the casing	mm
Max angle of the well bore	degree
Production formation	m
Total formation thickness	m
Effective oil saturation	m
Perforation intervals	a.o. m
Perforation intervals
Perforation intervals
Perforation intervals
False Bottom (initial / current)
Tubing length	m
Inner diameter of the tubing	mm
Oil Water contact (OWC), initial	a.o. m
Oil Water contact (OWC), current	a.o. m
Formation pressure, initial	atm
Formation pressure, current
Bottom hole pressure, initial
Bottom hole pressure, current
Wellhead (buffered) pressure initial, Mpa (atm):
Wellhead (buffered) pressure current, Mpa (atm):
Surface Pressure (between casing/tubing - Initial)	atm
Surface Pressure (between casing / tubing - Current)	atm
Temperature of the formation	°C
Lithology and geological index of the formation
Porosity type
Porosity	%
Permeability	millidarcy (mD)
Type of pumps
Diameter of connector	mm
Water column, initial/current	m
Dynamic water column, initial/current	m
Liquid production, initial/current	m³/day
Oil production, initial/current	m³/day
Gas production, initial/current	m³/day (x1000)
Water production, initial/current	m³/day
Water cut, initial/current	%
Gas factor, initial/current	%
Saturation pressure	atm
Formation/surface oil density	g/cm³
Surface gas density	g/cm³
Formation/surface oil viscosity	mPa x sec/mm²/sec
Parafin content	%
Temperature crystallization of paraffins	°C
H2S content	%
Current condition of the well	in service
Daily well data (* attach separate file)	available
Borehole graphic log (*attach separate file)
Additional information
Estimate of well casing condition
Perforator type
Number of perforations	number
Diameter of the perforation hole	mm
Angle of the perforation hole	degree
Depth of the perforation hole	mm
Intensification of the production:
a) Sulfuric acid treatment (solution volume)	cu m
Pressure (initial / current)	atm
b) Formation hydraulic break (solution volume)
Pressure (initial / current)
Other Treatments
Additional perforation	Multi Purpose Perforator Model 105C
Number of perforations	number
Diameter of perforation hole	mm
Angle of the perforation hole	degree
Depth of the perforation hole	mm

tube cleaning ultrasonic technology

A fragment of the pipe prior to treatment

A fragment of the pipe after treatment

Ultrasonic cleaning of pipes

The experiment was carried out under stationary conditions in the laboratory of Progress Industrial Systems SA on October 12, 2011.

Complete set:

Ultrasonic instrument with centrator, 2 pcs.
Clutch cable input and the instrument connection, 1 pc.
Vehicle with a winch, and pushing an ultrasonic generator, 1 pc.
Vehicle-tank for collection (filtering) of dirty water, 1 pc.
Individual power source + 3-phase voltage stabilizer, 1 pc.
Auxiliary tools and equipment, in stock

Technological cycle:

Cable entry fittings and tools are being installed at the cleaned pipe
Ultrasonic tool is introduced through the coupling to the cleaned tube
Dirty water collection hose is connected
A solution facilitating the ultrasonic cleaning is fed to the tube.
After filling the pipe section is to be cleansed
The ultrasonic instrument and pushing (pulling) winch is switched on after the filling the pipe section to be cleansed.

Complex specifications:
Ultrasonic instrument capacity – 2500 W. Maximum length of the cleaned section -7000 m maximum diameter of the cleaned pipe – 250 mm. Speed of tubes cleaning 0.1 to 3 m / min

On request it is possible to produce ultrasonic tools for cleaning of pipes of up to 1500 mm diameter.