MWD Instrument Lithium Battery User Guide (YST-48R)
Some contents are common to other MWD battery packs
Chapter 1 Overview of Lithium Batteries
1.1 Overview of Lithium Batteries
At present, most MWD instruments at domestic China and abroad are powered by high-temperature lithium-thionyl chloride batteries. Lithium-thionyl chloride batteries have the highest specific energy, highest voltage, long storage life and wide operating temperature range (normal -50 to +75 ℃, the high temperature can reach +150℃), the new high-energy primary battery with stable discharge voltage and high current discharge is also the most outstanding performance among lithium batteries, especially its high-temperature performance is still irreplaceable.
Various lithium batteries have been widely used in various fields as high-energy new energy sources. Lithium batteries are safe to use under normal conditions. However, due to the materials used in lithium batteries, the current safety problems have not been completely solved. Under certain conditions (such as short circuit, overload discharge or over discharge, charging, high temperature, shock and vibration, etc.), the battery may heat up. , expansion, leakage, explosion and other safety accidents.
Lithium-thionyl chloride battery is composed of metal lithium as the negative electrode; microporous carbon electrode as the positive electrode; lithium tetrachloroaluminate as the electrolyte, thionyl chloride as the solvent and the electrolyte composed of the active material; glass fiber felt as the separator, etc. The electrochemical device is sealed in a stainless steel case. Due to the characteristics of high-temperature lithium sub-battery, explosion-proof devices such as vent valves cannot be installed on the battery. Once it explodes, the destructive power is greater than that of other batteries.
Therefore, developing and producing safe and reliable lithium batteries, doing a good job in matching and power management between lithium batteries and instruments, improving safety awareness, and standardizing the use of lithium batteries should be highly valued by battery manufacturers, instrument manufacturers and battery users. problem.
1.2 The main factors affecting the safety of lithium batteries
There are many factors that cause lithium battery safety accidents. At present, some of the mechanisms have not been thoroughly investigated. According to the available information, the main factors affecting the safety of lithium batteries are summarized as follows:
The direct cause of the explosion of lithium batteries is thermal runaway. Lithium is an active metal. Lithium and nitrogen, oxygen, sulfur, chlorine, sulfur dioxide, etc. all undergo exothermic reactions to form compounds, some of which are unstable and some of which have explosive nature. When there are internal and external factors that cause the thermal reaction to run out of control, the internal pressure of the battery rises sharply, and an explosion occurs.
In order to avoid safety accidents when using lithium batteries, special attention should be paid to the following issues:
1.2.1. Battery short-circuit: When the battery is short-circuited internally or externally for any reason, the heat in the battery rises rapidly due to the violent reaction. The melting point of metal lithium is 180.5°C, and the battery will explode when the temperature reaches it. Although protective devices such as fuses are installed on the battery, any protective measures are limited, so special attention should be paid to preventing short circuits during storage, transportation and use.
1.2.2. Overload discharge: When the continuous power consumption of the instrument exceeds the specified discharge current of the battery, it is overload discharge. During overload discharge, because the discharge current density between the positive and negative electrodes is too high, heat will be generated, and the battery will explode when the heat accumulation for a long time reaches the limit that the battery can withstand. The common causes of overload discharge are: poor insulation of the power supply wires of the instrument string to form an incomplete short circuit; poor contact of the electrical connectors; The working current of the instrument increases, etc. Therefore, it is very important to check the insulation and continuity of the wires of all parts of the instrument string before use, whether the electrical connectors are normal, and whether the working current of the instrument is normal.
1.2.3. Overdischarge: Overdischarge refers to the excessive use of the battery. The capacity of the battery is limited. When the capacity of the battery is exhausted, if the battery continues to be forced to discharge, the battery will heat up. When the heat accumulation for a long time reaches the limit that the battery can withstand, the battery will explode. The common causes of over-discharge of batteries are as follows: long-term use, the battery is not replaced if the power is too low; after the instrument is used, the power supply is not cut off for a long time, causing the battery to be in a state of discharge; the new battery is mixed with the old battery; The consistency of battery capacity is not good, causing the capacity of individual cells in the battery pack to be used up in advance.
1.2.4. Charging: Lithium thionyl chloride battery is a primary battery and cannot be charged. If the battery is charged by mistake, the battery may overheat and explode. The common reasons for the wrong charging of the battery are as follows: there are other power sources in the power supply system of the instrument that may charge the battery; when the batteries are used in parallel, the anti-reverse charging diode is not installed or the diode fails; artificially charging the battery by mistake, etc.
1.2.5. Shock and vibration: Strong shock and vibration is an important cause of battery explosion. The internal structure of the battery is composed of a positive electrode sheet, a separator and a negative electrode sheet, and the separator is located between the positive and negative electrode sheets. Strong shock and vibration may cause some weak parts of the diaphragm to rupture, causing the positive and negative electrodes to contact and cause an internal short circuit to cause an explosion. Especially in the middle and late stage of battery discharge, the free electrolyte in the battery decreases, the concentration of the battery reaction product dissolved in the electrolyte increases, and the sulfur produced by the reaction will precipitate and adhere to the positive electrode and the diaphragm. The contact of metal lithium reacts violently, resulting in thermal runaway and battery explosion. Therefore, used batteries are more dangerous than new batteries in the event of shock and vibration.
1.2.6. Excessive temperature: In addition to the above reasons, which may cause the battery to thermally runaway and cause an explosion, the battery’s high ambient temperature may also cause an explosion. Lithium sub batteries are marked with the highest operating temperature of the battery, such as 70°C, 125°C, 150°C, 165°C, etc. It should be strictly controlled and used under the specified ambient temperature, otherwise it may explode.
1.3 Performance Index
The YST-48R mud pulse inclinometer while drilling MWD battery package performance indicators of the lithium battery are:
1.3.1. Open circuit voltage: 28.8V
1.3.2. Load voltage: ≥24V when the load is 400mA
1.3.3. Maximum working current: 500mA
1.3.4. Maximum pulse current: 2A
1.3.5. Battery working time: when the average working current is less than or equal to 120mA, the accumulated working time is greater than or equal to 200 hours, (Note: the accumulated working time is less than or equal to 130 hours when using with gamma)
1.3.6. Maximum working temperature: 150℃
Please read the above indicators carefully before use, and use within the specified range to ensure safety.
Chapter 2 Lithium battery pack testing and installation
2.1 Test of lithium battery pack
Regardless of whether a new battery or a re-used battery is used, it should be tested before use. The test content includes:
2.1.1. Appearance: Before installing the battery into the instrument, check the following contents: the outer packaging of the battery pack is not damaged; the appearance of the battery pack is free from contamination, deformation, and clear identification; the wires and connectors must not be rusted, dirty, or damaged. There are hidden dangers that may cause a short circuit or an open circuit.
2.1.2. Test continuity: Use a special test box to connect the plug of the test box with the corresponding plug of the battery. Turn the multimeter to the ringing Ω position, and use the test pen to measure the resistance between the upper and lower holes 1-1, 2-2, 3-3….8-8 must be <1Ω.
2.1.3. Test insulation: Use a special test box to connect the plug of the test box with the corresponding plug of the battery. Rotate the multimeter to 200MΩ, fix it in hole 1 with a test lead, and measure the insulation resistance between holes 3, 4, 5, 6, 7, and 8 and the metal terminals at both ends of the battery pack with another test lead. Must be ≥20MΩ ; Then measure between holes 2, 3, 4, 5, 6, 7, 8 and the metal terminals at both ends of the battery pack, and so on, to test whether the insulation between the holes is normal. Pay special attention, because holes 1 and 2 are the positive and negative poles of the battery, you cannot test the insulation resistance between holes 1 and 2, otherwise it will cause a short circuit. If it has been tested that the continuity is normal, only the upper row of holes can be tested.
2.1.4. Test the open-circuit voltage: test the open-circuit voltage of the battery after the continuity and insulation are normal. Turn the multimeter to the DC voltage level, insert the positive test lead into 2 holes, and the negative test lead into 1 hole, the voltage should be ≥28.7V. For batteries that have been put on hold for a long time or have been used in a well, the open circuit voltage may increase slightly, and it is normal to reach more than 29V. If the open circuit voltage is lower than 28.7V, the battery is low or faulty.
2.1.5. Test load voltage: test the battery load voltage after the open circuit voltage is normal. The test method is the same as the open circuit voltage. Press the load button on the test box to test the load voltage should be ≥24V. Due to the characteristics of lithium-thionyl chloride batteries, the open circuit voltage of the battery is still normal when the battery capacity has been basically discharged. Therefore, only the open circuit voltage is normal can not judge the battery is normal, the load voltage must be tested at the same time. Since the lithium-thionyl chloride battery is left for a long time or passes through a high temperature environment, a passivation film will be formed on the surface of the metal lithium, and the test load voltage will be lower at this time, which is a normal hysteresis phenomenon. After loading (press and hold the load button and do not release), the load voltage will return to normal, and the loading time varies from 1 minute to 10 minutes. If the load voltage does not rise but falls after being loaded for a long time, it means that the battery can no longer be used.
All the above tests are normal batteries, and the protective cover on the plug should be installed after the test. Abnormal battery, record abnormal phenomenon and data, restore the original packaging and hand it over to professionals.
2.2 Battery Canister Installation
The installation of the battery cartridge must be carried out in strict accordance with the installation instructions of the instrument. Pay attention to the following matters during installation:
2.2.1. Before installation, it is necessary to check whether the inside of the battery canister is clean, without water droplets and carbon deposits, and the battery canister must not have blisters or damage. Record the product batch number on the battery for future reference. Save the battery in its original plastic tube and protective sleeve for later use.
2.2.2. Use the test box to check the continuity and insulation of the plugs at both ends of the shock absorber assembly (4804007) before installing the battery.
2.2.3. The protective cover on the plug cannot be removed during the installation process. When removing it, special attention should be paid to the fact that pins 1 and 2 on the plug cannot touch, otherwise it may cause a short circuit of the battery.
2.2.4. If the resistance is too great when the battery is inserted into the battery canister, it cannot be forcibly inserted, the reason should be found out, and the obstacle should be removed before installation.
2.2.5. The transition outer cylinder at one end of the battery 6-pin 4-hole plug (pigtail cable) should be tightened at the end, otherwise the braided cable may be twisted and broken, resulting in a short circuit of the battery.
2.2.6. It must be checked whether each O-ring needs to be replaced. It is recommended that a new O-ring be replaced every next well.
2.2.7. When installing the transition outer cylinder, the battery cylinder should be fixed by means of back clamps, and it is not allowed to hold the battery cylinder or ride on the battery cylinder.
2.2.8. After the battery canister and the transition outer canister are installed, test the continuity and insulation of both ends with the test box again. The test method is the same as the battery test method. Backup after the test is normal.
2.3 Connection and test of battery cartridge and instrument
The connection between the battery canister and the instrument must be carried out in strict accordance with the instrument installation manual. Pay attention to the following matters during installation:
2.3.1. The ground simulation test of the downhole instrument assembly must be carried out to confirm that the instrument is working normally; the components with wires such as the centralizer can be connected to the outer battery cylinder after the insulation and conduction are normal.
2.3.2. After the battery cartridge is connected to the downhole instrument assembly, it is not connected to the fishing head for the time being, and the plug of the special battery working current test box is connected to the plug on the centralizer. The current state of the circuit is the same as the state after the fishing head is connected. Again, the instrument is connected to power from the battery. Carry out the power-on work test according to the instrument manual. Pay attention to the reading of the ammeter on the battery working current test box. The continuous current should be less than 130mA (less than 185mA when gamma is added), and the pulse current when the servo valve head operates should be less than 1.5A. If the working current is too large, the instrument should be checked for failure and cannot be used forcibly. Otherwise, the battery will be used for a short time, affecting the work of the downhole instrument, and even cause a safety accident due to the overload discharge or overdischarge of the battery.
2.3.3. After testing that the working current of the battery is normal, connect the salvage head and continue to operate according to the instrument manual.
2.4 Using the battery and removing the battery holder
2.4.1. Use of battery
- a) Abnormal shock and vibration should be avoided during battery use.
- b) It is strictly forbidden to use and store the battery in an environment exceeding 150°
- c) Stop using it when the battery load voltage is found to be lower than 20V during use.
- d), record the battery usage time and status in detail. If the time of going down again may exceed 200 hours, the battery needs to be replaced.
- e) When the outer cylinder of the battery is found to be damaged, it shall not be used in the well again.
- f) The battery should be disassembled in time after use, and should not be left connected to the instrument for a long time.
2.4.2. Removing the battery canister
The disassembly of the battery cartridge must be carried out in strict accordance with the installation instructions of the instrument, and the following matters should be paid attention to when disassembling:
a) The operator must wear protective clothing, gloves, protective glasses and earmuffs, and the disassembly operation should be carried out outdoors as much as possible. Before disassembling, check the appearance of the battery outer canister. If the battery canister is found to be hot, personnel must quickly evacuate the site and return after observing for at least 4 hours without any abnormal changes. If it is found that the battery canister is damaged, smells bad or has traces of high temperature on the surface (burning blue), you should also observe that there is no abnormal change for at least 4 hours before disassembling it carefully. If it is difficult to disassemble, do not forcibly disassemble the battery holder to avoid safety accidents.
b) When removing the battery canister, use the back clamp to fix the battery canister, and do not hold the battery canister or ride on the battery canister.
c) Since there may be high-pressure gas in the battery canister, the operator should stand on the side of the longitudinal axis of the battery canister when disassembling the battery canister, and slowly rotate the clamp to avoid high-pressure gas leakage in time.
d), first remove one end of the 6-pin 4-hole plug (pigtail cable). After disassembly, if the battery is found to be damaged, do not forcefully disassemble the other end to avoid safety accidents.
e) After removing the battery, immediately install a protective cover on the plugs at both ends of the battery (wrap with insulating tape if there is no protective cover), and store it in a packaging plastic tube.
Chapter 3 Safety Precautions for Battery Use
3.1 Transportation, Storage and Handling of Lithium Batteries
3.1.1. Air Freight
Internationally, there are strict regulations on the air transportation of lithium batteries. Due to the heavy weight of lithium in MWD battery packs, air transportation is generally not possible.
The shipping regulations of lithium batteries are stipulated in the International Maritime Dangerous Goods Code (IMDG) (12) published by the International Maritime Organization (ICAO) and can be transported.
3.1.3. Land transportation
The regulations for the transportation of lithium batteries by road and rail vary from country to country, and railway departments such as China Railway Express refuse to transport lithium batteries. Domestic transportation generally adopts road freight, and must comply with relevant national laws and regulations during transportation.
3.1.4. Lithium batteries must be transported in their original packaging, and must not be exposed to sunlight, heavy pressure, rain, damp, impact or brutal handling.
3.1.5. Storage of lithium battery
- a) The battery is stored in a ventilated, dry and cool environment. High temperature or high humidity may cause battery performance degradation and/or battery surface corrosion.
- b) The stacking height of battery boxes shall not exceed 5 boxes. Too many battery boxes are stacked on top of each other, and the lowermost battery may be damaged.
- c), the battery should be kept in the original packaging. Batteries may be shorted or damaged if they are unpacked and mixed together.
3.1.6. Disposal of lithium battery
- a) Do not disassemble the battery. Certain components in lithium batteries are flammable, hazardous and can cause injury, fire, rupture or explosion. However, lithium batteries do not contain harmful heavy metals such as cadmium, mercury, and lead.
- b), do not burn the battery. Lithium burns violently, and lithium batteries explode in fire. The combustion products of lithium batteries are toxic and corrosive.
- c) Store the recovered lithium battery in a clean, dry and well-ventilated environment, away from direct sunlight and extreme heat sources. A used battery may have residual charge, and dirt and moisture can cause the battery to short-circuit and heat up, causing the battery to leak, rupture, or explode.
- d) Do not mix recycled batteries with other materials. If the battery is shorted, the heat generated can ignite flammable waste such as greasy rags, paper or wood and start a fire.
- e), protect the extremes of the battery. Protect battery terminals with protective sleeves or insulating material to prevent battery short-circuits from leaking, bursting, or exploding.
3.2 Lithium battery usage time
The use time of the lithium battery is related to the working current of the instrument. For example, if the average working current of the instrument is less than 120mA, the cumulative use time of the battery can reach more than 200 hours. If the average working current of the instrument is greater than 185mA, the accumulative battery usage time will be less than 130 hours. Different models of instruments have different working currents, even if the instruments of the same model have differences between each set of instruments. Therefore, it is very important to detect the working current of the instrument before use to estimate the battery life. Correctly predicting the battery usage time can avoid tripping due to the battery running out of power in the middle, and more importantly, it can prevent the battery from causing safety accidents due to overload discharge or forced overdischarge.
3.3 Handling of Lithium Battery Safety Accidents
3.3.1. Lithium battery leakage. The battery is ruptured and electrolyte, gas or other substances leak out. The electrolyte of lithium-thionyl chloride battery is highly corrosive, and when it encounters water vapor, it generates irritating sulfur dioxide and hydrogen chloride gas. If the battery is found to be leaking, the personnel should be evacuated immediately, and the irritating gas will be dissipated before disposal. If it gets on the skin, it should be rinsed immediately with plenty of water, and then treated by scalding. Leaked batteries or battery cartridges containing leaked batteries should be moved to a safe place outdoors for at least 72 hours and then buried deep.
3.3.2. Lithium battery exploded. The most obvious sign before the battery explodes is fever. When the battery or battery cartridge is found to be hot, the personnel should be evacuated immediately and observed for more than 4 hours before disposal without danger. A battery explosion can cause the same damage to people as other causes of the explosion. In case of personal injury, emergency treatment such as hemostasis and immobilization should be performed immediately and sent to the hospital for treatment. Exploded batteries or battery cartridges containing batteries should be moved to a safe place outdoors for at least 72 hours before being buried deep.
3.3.3. The battery has exploded underground. Do not disassemble the battery canister. The battery canister with batteries should be moved to an outdoor safe area for at least 72 hours and then buried deep.
3.3.4. Operators must wear protective clothing, protective glasses, gas masks and gloves when dealing with the above accidents.
3.3.5. If you find that the battery has no power, poor contact and other faults, do not disassemble the battery without authorization, but hand it over to professionals or manufacturers for handling.
3.3.6. If the battery has no voltage because the fuse is blown, check the instrument and all the connecting parts for short circuit, poor insulation, virtual connection, etc., otherwise the failure may occur again. In particular, do not arbitrarily replace the fuse with a larger fuse current than the original one.