Thirty logging methods after drill pipe drilling

2019-12-02 17:32:25

Well logging, also known as geophysical logging or field geophysics, is a method of measuring geophysical parameters using the electrochemical, electrical, acoustic, radiological, and other geophysical properties of rocks. It is an applied geophysical method (including gravity, magnetism, electricity, earthquakes and nuclear energy). In short, logging is the measurement of physical parameters of formation rocks.

Record principle

The basic units of any substance are molecules or atoms, which in turn include nuclei and electrons. Rocks conduct electricity. We can measure resistivity by delivering a current into the formation, and neutron porosity and density can be measured by bombarding the formation with high-energy particles. The strata contain radioactive material and are radioactive (). ACTS act as a medium for the propagation of sound waves and can measure the velocity of sound waves in the strata. The water in the formation contains ions that move with the ions in the mud in the well, creating currents that can be measured as high or low (spontaneous potential).

Logging classification

When drilling, logging must be done after drilling to the designed depth of the well to obtain a variety of geological and engineering data that can be used as the primary data for completion and geological development. This type of log is often referred to as an open hole log.

Open hole logging: logging in newly drilled Wells without casing.

According to the basic principles of physics, open hole logging methods are divided into four categories:

Casing logging: the logging is performed after the casing is closed.

Wireline logging: lowering and lifting of logging instruments by cable.

Non-wired logging: simultaneous drilling (mud, drilling, logging, logging while drilling).

Engineering logging method and detection

1. HRAT- high resolution acoustic downhole television

The high resolution acoustic downhole television tool (HRAT) provides continuous high resolution directional ultrasound images of the wellbore. The shaft wall is scanned with a focused ultrasonic beam using a stationary acoustic generator and a rotating acoustic transmission mirror. The amplitude and propagation time of sound waves emitted from the borehole wall are recorded as separate image records. Features such as fractures reduce reflection amplitude and show dark sinusoidal trajectories in well logs. The travel record is equivalent to a high-precision 360-arm caliper and shows the diameter variation of the open crack and "crack". The recorded direction information can be used to guide the image in real time.

2. Hi-optv- high resolution optical downhole TV

The high resolution optical downhole television tool (hi-optv) USES traditional light sources to provide continuous very high resolution borehole wall imagery. A unique optical system based on the reflection principle of the hyperbolic mirror ensures that the probe can simultaneously measure 360 degrees. The measured data is processed in real time to extend the complete borehole wall image in the magnetic north direction. The probe resolution is better than high-resolution acoustic downhole television (HRAT) and can produce vivid color images.

Gamma rays

GR is a measure of radioactivity in rock formations, and clay is the most radioactive material in rocks. Generally, mudstone GR is high and sandstone GR is low.

4. Cgr-natural gamma spectrum

Natural gamma ray spectral logging is a logging method to record natural gamma rays in different energy ranges. Since most of the gamma rays emitted from the formation are produced by the decay of three radioactive isotopes of potassium, or, and uranium, the natural gamma ray spectral log provides insight into the levels of potassium, th, and uranium in the formation. These data are very useful for accurate determination of reservoir shale content, analysis of sedimentary environment and oil generation conditions, and classification of lithology.

5. Calibrate three arm diameters

Calipers are measures of hole size. For example, in a hole drilled with an eight-and-a-half inch drill, the measured aperture is eight and a half inches, greater than eight and a half inches (called dilatation) or less than eight and a half inches (called dilatation). Reduce). The measured aperture is an intuitive understanding of the aperture.

6. Borehole geometry logging

Borehole geometry tool consists of four - arm inclinometer and vertical log module. The tool is an alternative to the three-arm caliper (measuring 710mm), which has the advantage of providing accurate information about the deviation between the hole cross section and the circular pattern, as well as directional information needed for completion studies and formation stress analysis. The top can be recorded as standard perpendicularity.

7. Four-arm inclinometer

Consisting of a microresistivity test section and a detachable and detachable vertical logging module, microresistivity data is collected from four high-resolution button downward contacts mounted on the motor-driven x-y caliper support arm. With electrodes at different depths, flat structural features can be detected that are not perpendicular to the borehole axis. By combining the data of the four microresistivity and the data of the verticality module, the formation dip Angle and tilt azimuth Angle relative to the borehole axis are calculated.

8. Ac compensation sound wave/CBL

Sound waves are the time difference between sound waves, measured in s/ft. The time difference between sound waves is small, which means that sound waves travel through the formation for a relatively short time, indicating that the formation is relatively dense and hard. Instead, the layers are relatively loose.

9. TRGS- three arrays of sound waves with complete waveforms

Transmission time and full waveform data are obtained from a single transmitter and three receivers.

DEN- formation density, density shield logging, iron ore density probe

Radioactive sources bombard strata with high-energy particles to measure density, the density of solid and fluid rock per unit volume.

11. CNL- dual neutrons

Neutrons, also known as neutron porosity or total porosity, are measured by bombarding atoms in the formation with high-energy particles from a radioactive source, expressed as a percentage of the fluid volume in the rock.

12. Neutron | neutron SP/SPR

The neutron probe provides a qualitative porosity log under most drilling conditions for metal, plastic, and drill pipe drilling conditions. The dual-neutron probe provides compensated neutron porosity measurements by borehole alignment in open hole mud Wells. It is the preferred probe for quantitative study of formation porosity fluid.

13. Electric logging

Electrical logging probe (ELOG) is a classic well combination probe that provides shallow, middle and deep resistivity measurements with self-potential (SP). The low-frequency bidirectional current on the probe electrode source returns through the formation to the cable armor above the insulation head. The potential caused by the current is measured on the various induction electrodes of the probe and the grounding voltage value is used as a reference. These measurements are converted in the probe to represent formation resistivity and transmitted to the surface.

14. Centralized electrical logging (shielded logging)

Resistivity is divided into micro transverse and double transverse (including shallow transverse and deep transverse). The difference is the depth of the sound. Deep lateral sounding depth is the maximum, followed by shallow lateral sounding depth, and the minimum lateral sounding depth is the minimum. Due to the different ways mud penetrates into the formation, the borehole is the center of a circle with different radius. The formation is completely penetrated by mud, partially penetrated by mud, but not by mud, which corresponds to the formation detected in the formation. Micro side, shallow side and deep side.

15. Dual focus induction tool/ultrafine induction tool

The dual-focused induction probe provides two conductivity records corresponding to the "medium" and "deep" resistivity measurements, respectively. In porous permeable formations, drilling fluids permeate to form "invasion zones" with different electrical properties. These two depths and two depths can obtain the formation electrical characteristics of different depths. 1 "focusing induction probe provides only a single medium penetration conductivity record. Suitable for conductivity/resistivity measurement of boreholes for fine hole drying or plastic casing (mainly for mineral exploration).

16. Vertical probe

Vertical logging tools can accurately and continuously measure the inclination and direction of a well. This data can be used as a direct output of the log trace file, or it can be further processed into tabular and graphical outputs, including drill hole locations, drill hole offsets, and true vertical depths.

17. Gyro-verticality and magnetic three-component logging

The gyroscope vertical probe can obtain the borehole inclination/azimuth log data when the metal casing or magnetic material around the borehole cannot be used with the standard vertical probe.

The gyro magnetic three-component probe is used to collect the three-component parameters of the magnetic field as well as the inclination and azimuth of the well.

18. Thermal conductivity probe

The sensor is located in an insulated box at the bottom of the probe. During logging, fluid flows freely through the sensor through vents at the bottom of the lower side and above the probe. The probe should be recorded from top to bottom to reduce interference with fluid interference.

19. Small source density probe

The small-source density logging probe USES a very low-intensity 60Co light source to provide high-quality calibration and in-hole compensated density logging at a reasonable rate, which in many areas does not require a radiological license.

20. Density gamma probe

When hole diameter is limited, density/gamma probes (also known as tri-probes) replace standard formation density probes for convenience and low cost. And the probe's qualitative density measurement has been accepted by the customer. Logging using an unprotected core probe through a borehole casing is

21. Water quality probe

The probe can contain seven special sensors to measure fluid characteristics. New solid film sensors have been found, and the low drift of electronic equipment can be eliminated from the complex calibration work. Calibrate measurements to standard temperature and pressure values.

22. Water and natural gas sampler

Water sampler: the water sampler consists of a chamber with an electric valve at the top and bottom of the probe. When the probe is placed in the well, the valve remains open and fluid from the well flows freely into the chamber. At the required test depth, the ground control system starts the motor and closes the valve to seal the chamber to ensure the sample is extracted.

Gas sampler: the RG gas sampler is designed to recover uncontaminated samples of good fluids containing or containing gas while maintaining original well pressure. The probe contains a sealed sample chamber with a movable piston and an electric valve. Before recording, remove the piston manually and lock in place, leaving a partial vacuum in the sample chamber. During the sampling process, the valve opens under ground control and the well fluid enters the chamber. Then close the valve and seal the sample under ambient pressure. On the ground, the fluid can still be transferred under pressure to the appropriate container for analysis.

23. Impeller flowmeter

The probe is fitted with a lightweight spiral impeller mounted on a double sapphire bearing. The impeller contains magnets for driving the hall effect switch in the probe to detect whether the impeller is rotating. A separate recording channel records rotation times to improve resolution at high and low velocity based on fast and slow timelines. Distinguish up and down rotations in the detector.

24. Heat pulse flowmeter

The probe consists of a horizontal grid heating element and two thermistors located above and below it. A hole in the probe allows fluid to flow freely. At the command of the ground system, pulses of current are applied to the heating grid, the liquid near the grid. The movement of the thermal current front towards the thermistor is detected. The upper or lower thermistors first detect the hot fluid, depending on the direction of the flow. The time difference with the thermistor allows flow to be calculated.

25. Microresistivity probe

Resistivity measurements are based on shielded measurements, where the ring electrode remains at the same potential as the central measurement electrode, forcing the measurement current to form a narrow current beam. These electrodes are mounted on an elastic plate, mounted on an electric jack and kept close to the wall by the spring pressure when measured. The calipers use the same mechanical principles as the shaft. Optional gamma ray measurements can help determine correlations with other logs.

26. Excite the polarization probe

A probe used to measure the accumulated charge of low-frequency alternating current through pores, saturated water, and mineralized rocks. The main reason is the electron transfer effect caused by the polarization current, which mainly occurs in the contact between iron metal and semiconductor metal ore body particles.

Two external measuring electrodes in the probe excite controlled alternating current through the rock. After the external power supply is removed, voltage changes over time are measured through the probe's two internal electrodes. The integral area under the voltage-time curve is a measure of the charge rate.

27. Susceptibility probe

The probe is a low frequency instrument specially designed for exploration. The probe has excellent stability under pressure and temperature changes.

The vibrating magnetic field induces the changing current in the forming ring at a certain distance around the probe coil, and the secondary magnetic field generated by the current is detected by the receiving coil. The in-phase information is the magnetic reflection of rocks in the formation ring.

28. P-s suspension probe

The p-s suspension probe is a low-frequency acoustic probe designed to measure compression and shear wave velocities in soil and soft rock formations. It USES indirect excitation rather than mode switching in conventional sound waves, and can obtain high-resolution P and S wave data up to 600 meters deep in a water-filled borehole.

29. Sonar caliper probe

Sonar logging probes have been successfully developed to provide extended and directional cross sections of large holes, shafts, caves and trench walls. Precise diameter measurements are combined with an omni-directional 360° view of the hole. The 700kHz and 200kHz probes can be used to adapt to different field fluid conditions.

Sonar probes work by emitting sound pulses that are reflected off solid objects. The delay time between the timing emission and the reflection of the sound wave reaching the probe is used to calculate the distance. The sonar caliper probe makes 400 separate radius measurements at 360° radians around the probe and then directs it to magnetic north.

30. Side pressure gauge probe

A side pressure gauge is a borehole side gauge with a side gauge designed to characterize ground deformation from soft to hard rock. Analysis of formation deformation characteristics is critical for the construction of large structures such as DAMS, Bridges, and high-rise buildings. The construction of large structures such as DAMS, Bridges, and tall buildings is critical.

The parametric probe has a series of probes that provide rock pressure characteristics around the BQ (60 mm), NQ (76 mm), and HQ (98 mm) wellbore. Electrical sensors are used to measure rock pressure and displacement directly in the probe. The arm is used to measure displacement, making maintenance easier. The applied pressure is measured by a precision semiconductor sensor in the probe. Pressure gauge and data recorder: this system is equipped with data recorder, probe and cable, up to 200 meters.