Since 1990s, slim hole drilling technology has made great progress as an economical drilling technology. The development of this drilling technology promotes the technical progress of slim hole drilling equipment and supporting tools, which in turn promotes the further development of technology. At present, the latest progress of slim hole drilling equipment and supporting tools is mainly manifested in the following aspects.
Slim hole drilling rig
Slim hole drilling methods include rotary drilling, downhole motor drilling and continuous coring drilling. Its supporting slim hole rigs include small conventional oil rigs, mining continuous coring rigs, workover rigs, coiled tubing operators and special slim hole rigs. Sweden, the United States, Germany, Canada, Belgium, Italy, Australia and Romania have all developed and applied new slim hole oil rigs, but generally speaking, there are few dedicated slim hole rigs, and improved slim hole rigs still account for the majority.
At present, the representative slim hole drilling rigs of foreign companies mainly include: low-cost Kenting slim hole drilling rig in the United States; The slim hole hydraulic drilling rig of Swedish Petroleum Exploration Company is equipped with a small blowout preventer, which can drill slim holes with a diameter of 50.8-76.2mm and a depth of 2 17-2666. Foraslim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim. Slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim slim The SH 1 1 slim hole oil drilling rig jointly developed by AMOCO and NABOR Company is equipped with numerical control system and expert well control system, which is fully hydraulic driven and the drilling fluid purification system is cleaner and more centrifugal. The slim hole oil drilling rig developed by European planning project adopts top drive system, SH11and SH66 high-strength drill pipe, and is also equipped with coring device, mud logging and logging device, and kick monitoring and alarm system. The slim hole drilling rig developed by British drilling equipment company is driven by hydraulic pressure, and the drilling depth can reach 3000M m m. The new drill pipe discharge system and advanced testing instruments can not only drill, but also core.
Slim hole downhole drilling tool assembly
1. Slim hole bit
(1) roller bit At present, the improved tungsten carbide alloy insert (TCI) roller bit is used abroad, such as the roller bit developed by Baker Company of the United States, which can adapt to the rotation speed of 200 r/m 98.4 m, the cone shell thickness is small, and the bit length is reduced from the conventional 146mm to12/kloc-. Judging from the current development, single-cone bit will become a low-cost and high-efficiency drilling tool, which is suitable for slim hole drilling in various formations. Canada uses a single-cone bit to study abrasive hard sandstone, and the footage of a single-cone bit is equivalent to the total footage of two three-cone bits.
(2) Diamond bits, anti-deflection small-size pdc bits, thermally stable polycrystalline diamond bits (tsp) and natural diamond bits represented by dbs Company and christensen Company have been specially developed. This bit can adapt to high rotation speed and can be used for continuous coring and drilling. The new pdc polycrystalline diamond bit tsd diamond bit has good drilling and reaming effect in deep and medium hard strata, and is superior to ordinary pdc and tsd bits in reducing torque and cooling the bit. The diamond bit with dome design has a more compact wear-resistant structure and is more suitable for drilling hard rocks. Amoco also developed an anti-whirl drill bit to avoid premature damage of small polycrystalline diamond, and made a breakthrough in penetration ability. Small polycrystalline diamond bit will become a development direction of slim hole technology.
(3) Hybrid pdc/tsp bit maurer Engineering Company of the United States developed a hybrid pdc/tsp high-efficiency bit for the US Department of Energy. PDC cutting teeth are placed in the front row of teeth to drill soft stratum at high speed; TSP cutting teeth are placed in the back row of PDC cutting teeth, which is used to drill hard interlayer that is easy to damage PDC cutting teeth. The drill bit can effectively crush rocks driven by a specific high-power motor.
(4) In the continuous coring operation of slim hole, 59% of wells with a depth of 1000-3000m use diamond coring bits, and the application of cemented carbide bits in slim hole coring is still under study. At present, a double-body bit has been developed abroad, which can improve the coring quality. The function of the drill bit can be changed by replacing the drill bit plug with a rope fishing device, so that the drill bit can be drilled or cored.
At present, 152.4MM roller bit, PDC bit, double-center eccentric BDC bit, fixed bit and single roller bit have been developed in China, but the service life of roller bit is far from that of similar products abroad.
2. Drilling fluid motor
At present, there are slim hole drilling fluid motors with high, medium and low speeds and various diameters abroad, and their high temperature resistance has exceeded 200 degrees Celsius. Maurer Engineering Company of the United States has developed an 85.73mm high-power slim hole drilling fluid motor for the US Department of Energy. Using pdc/tsp high efficiency bit, the ROP can be increased by 2 times, and the drilling cost can be reduced by 50-60%.
An instrumented downhole steering motor was developed by Anadrill Company of the United States and Shell Research and Development Institute of the United Kingdom to improve the effect of geo-steering. The combination of fixed motor and adjustable bending shell system can make the drilling tool have various deflecting functions, and the maximum deflecting rate can exceed 65438 0.5 degrees and 30.5 meters. Various slim hole drilling fluid motors have also been successfully developed in China.
3. Drill pipe
In order to adapt to slim hole drilling and minimize the drill string size in the whole drilling process, foreign countries have developed high-strength special drill pipes. Standard new drill pipes include slim hole high torque drill pipes with an outer diameter of 88.9 mm and a joint of 10 1.6- 127 mm, and drill pipes with an outer diameter of 65 mm specially designed for 85.73 mm in.
4. Downhole tools to reduce drill string vibration and fatigue damage.
In order to reduce the vibration and fatigue damage of drill string, the main supporting tools used at home and abroad are: anti-deviation PDC bit, flexible rotary table or top drive to reduce torsional vibration, drilling fluid motor and hydraulic booster, and new anti-fatigue drill pipe joint. Figure 1 shows the downhole hydraulic booster, which can prolong the life of the drill bit. In many formations, the drilling speed is 3-5 times faster than rotary drilling, and the drilling cost can be reduced by 50-70%. At present, there are hydraulic regulators in series, up to three stages at present, and the working principle is the same as that of single stage, except that the regulators need to apply a larger WOB.
5. Jet impactor
In the process of slim hole drilling, jet impactors are used together, and the combined drilling with impact H rotation can not only improve drilling speed, but also prevent well deviation, thus improving drilling quality and reducing drilling cost.
6. Slim hole fishing and jarring tools
At present, many kinds of fishing sleeves and jars suitable for slim holes have been developed at home and abroad, such as 104MM fishing sleeves for fishing 83.2MM and 89.6MM drilling tools, and various sizes of downhole circulating joints for high-pressure slim holes-hydraulic support joints, hydraulic fracturing disc joints and safety joints. There are two kinds of high-pressure slim hole jar: single action and double action. Domestic petroleum machinery factories such as Mudanjiang and Gao Feng produce slim hole fishing and jarring tools, but the materials are insufficient.
7. Slim hole drilling tool alarm system
At present, foreign countries have successfully developed a drilling tool alarm system for coiled tubing drilling in slim holes, which can detect the damage of coiled tubing and avoid serious downhole accidents. The system transmits the damage of coiled tubing to the ground control room through sensors in the wellbore, and provides visual and audible downhole drilling tool information to the operator from the instrument control panel.
Slim hole continuous coring device
Slim hole continuous coring technology originated from mining continuous coring technology, which is essentially wireline coring. Generally speaking, slim hole continuous coring device includes coring drilling rig, coring drill pipe, coring bit, core barrel and other necessary tools. Now it is possible to core in 104.8MM or smaller borehole, and the drill string anti-vibration technology is adopted to improve the core recovery rate. Amoco Company adopts a continuous coring drilling system with thin-walled drill pipe and cable recoverable core barrel for coring. The system uses top-driven rotary outer flat drill pipe, and the continuous coring length can reach 12. 19m, and the average coring yield of development wells is 98.3%. Fig. 2 shows the downhole assembly used by Amoco for slim hole coring. The development of conventional slim hole coring tools in China is mainly based on Sichuan Oilfield, such as Chuan 6-3. The Ministry of Coal has completed the development of rope coring tool.
Slim hole well control equipment
In order to ensure the safety of slim hole drilling, foreign countries have improved and perfected the blowout preventer and degasser for slim hole well control, and developed an advanced formation overflow detection system based on the principle of detecting drilling fluid flow in and out of the well and acoustic wave reflection. Foreign well control equipment includes: fully sealed and semi-sealed ram BOPs, bop in drill string, degasser and manifold required for dynamic balance well killing, and heavy drilling fluid with good performance is reserved.
The slim hole well control expert system developed by the company can be continuously monitored on site by computer: Gaskick system developed by smedving company; INTEQ company develops dynamic simulator and overflow detection software; Shell's well kick early detection system can detect the invasion of 0. 16 cubic meters.
The gas invasion detector while drilling was tested in Shengli Oilfield 1999. The portable computer is used for data processing and analysis, and the pressure wave generated by the drilling pump is used as the sound source of the detector. At present, gas invasion detector while drilling has been widely used in slim hole drilling and achieved good results. The successful development of this instrument is of great significance to improve the well control technology of slim hole and complex formation drilling in China.
Slim hole cementing tool
A new equipment has been successfully developed abroad, which can be used for cementing 50.8 mm coiled tubing slim hole. A special device consisting of J-groove at the end of coiled tubing and 65 mm seal can automatically connect or trip the sealed borehole sleeve at the end of 88.9 mm casing string. This tool can be recycled, easily adjusted and reused. In case of cementing accident, the coiled tubing can be cut out of the hole. This tool provides an economical cementing method when the conventional cementing method cannot be implemented.
Development suggestion
(1) In slim hole technology, perfect equipment and supporting tools are the key to technical development. At present, the special drill string for continuous coring in slim hole, the kick monitoring device when using oil-based drilling fluid, and the shoulder connection of drill pipe need to be further studied.
(2) Compared with foreign countries, domestic slim hole equipment and tools are not perfect, which limits the development of slim hole technology. At present, the slim hole tools that have been developed are mostly used in 152.4MM holes, and the specifications and models are single.
(3) Slim hole technology has low cost and will become the mainstream technology in petroleum industry. It is suggested that domestic oilfields should make the development plan of equipment and supporting tools according to the characteristics of low cost of slim hole technology, and accelerate the development and application of slim hole equipment and supporting tools.
(4) Judging from the current application of slim hole technology in China, there are still cases where the later operation tools are not matched with slim hole drilling tools, so it is suggested to strengthen the research and development of slim hole drilling and production integrated tools.
(5) From the point of view of reducing drilling cost and increasing ROP, it is suggested to speed up the improvement and development of slim hole drilling rig and the research of high-speed slim hole bit.