1. Drill bit
Bits are mainly divided into: scraper bit; Cone bit; Diamond bit; Carbide drill; special type
Drill bit, etc. The main indicators to measure the bit are: bit footage and mechanical ROP.
2. Eight pieces of drilling rig
The eight major parts of the drilling rig refer to: derrick, crown block, traveling block, hook, faucet, winch, rotary table and mud pump.
3. Composition and function of drill string
The common components of drill string are: drill bit, drill collar, drill pipe, stabilizer, special joint and Kelly. The basic functions of drill string are: (1) tripping the bit; (2) Apply WOB; (3) Transmitting power; (4) Transporting drilling fluid; (5) Carry out special operations: squeezing cement, handling underground accidents, etc.
4. Performance and function of drilling fluid
The main properties of drilling fluid are: (1) density; (2) Viscosity; (3) Yield value; (4) Static shear force; (5) Water loss: (6) mud cake thickness; (7) Sand content; (8) PH; (9) Solid phase and oil-water content.
Drilling fluid is the blood of drilling, and its main functions are: 1) carrying and suspending rock cuttings; 2) Cooling and lubricating drill bits and drilling tools; 3) Clean and flush the bottom of the well to facilitate drilling; 4) Use the pressure of drilling fluid column to prevent blowout; 5) Protect the shaft wall from collapse; 6) Transfer power for downhole power drilling tools.
5. Common drilling fluid purification equipment
Common drilling fluid purification equipment: (1) vibrating screen, which is used to remove sand particles larger than the size of the screen hole;
(2) The cyclone separator is used to remove particles smaller than the size of the screen hole of the vibrating screen; (3) Screw centrifugal separator is used to recover barite and separate clay particles; (4) Simple screen centrifugal separator is used to recover barite.
6. The circulation procedure of drilling fluid in drilling
The drilling fluid tank passes through the pump – ground manifold → Riser – hose and faucet → inside the drill string → drill bit – annular space outside the drill string → wellhead, mud (drilling fluid) tank → drilling fluid purification equipment → drilling fluid tank.
7. Damage of drilling fluid to oil and gas reservoir during drilling
The main damages are as follows: (1) solid particles and mud cake block the oil and gas channel; (2) The filtrate expands the clay in the formation and blocks the pores of the formation; (3) The ions in drilling fluid filtrate interact with formation ions to produce precipitation and block the channel; (4) Produce water lock effect and increase oil and gas flow resistance.
8. Methods of predicting and monitoring formation pressure
(1) Seismic method shall be adopted before drilling; (2) During drilling, mechanical ROP method, D and DC index method are adopted,
Shale density method; (3) After well completion, density logging, acoustic moveout logging, oil test and other methods are adopted.
9. Hydrostatic pressure of drilling fluid and its variation during drilling
Hydrostatic pressure is the pressure caused by the weight of drilling fluid itself. Changes during drilling, the entry of rock cuttings will increase the liquid column pressure, the invasion of oil, gas and water will reduce the hydrostatic pressure, and the decline of drilling fluid level in the well will reduce the hydrostatic pressure. The methods to prevent the change of hydrostatic pressure of drilling fluid include: effectively purifying drilling fluid; Fill up the drilling fluid in time when tripping out.
10. Jet drilling
Jet drilling is a drilling method that uses the hydraulic action of the high-speed jet generated when the drilling fluid passes through the jet bit nozzle to improve the mechanical ROP.
11. Factors affecting ROP
(1) WOB, rotating speed and drilling fluid displacement; (2) Drilling fluid properties; (3) Hydraulic power of bit;
(4) Rock drillability and bit type.
12. Composition of drilling coring tools
(1) Coring bit: used to drill core; (2) Outer core barrel: Bearing WOB and transmitting torque; (3) Inside
Core barrel: store and protect core; (4) Core claw: cut, support and take out the core; (5) There are also suspension bearings, water diversion head, back pressure valve, centralizer, etc.
13. Coring
Coring is to use special coring tools to take underground rocks into blocks to the ground during drilling. This kind of block rock is called core. Through it, we can determine various properties of rocks, intuitively study underground structures and rock sedimentary environment, and understand the fluid properties.
14. Balanced pressure drilling
During drilling, always protect the borehole pressure equal to – This drilling method is called balanced pressure drilling.
15. Blowout is the phenomenon that the fluid in the formation ejects from the ground or flows into other formations in the well. Blowout is caused by:
(1) Inaccurate control of formation pressure; (2) Low mud density; (3) The height of mud liquid column in the well decreases; (4) Pooh suction; (5) Other improper measures, etc.
16. Soft shut in
In case of overflow shut in, first open the throttle valve, then close the blowout preventer, and then close the throttle valve again. Because this can ensure that the shut in wellhead casing pressure value does not exceed the allowable wellhead casing pressure value and ensure the safety of well control. Once the pressure in the well is too large, it can save flow and blowout.
17. Overflow display during drilling
(1) The liquid level of drilling fluid storage tank rises; (2) The outlet flow rate of drilling fluid is accelerated; (3) Speed up or release
Empty; (4) The circulating pressure of drilling fluid decreases; (5) Downhole oil, gas and water display; (6) The performance of drilling fluid changes at the outlet.
18. Overflow shut in procedure
(1) Stop the pump; (2) Lifting Kelly; (3) Properly open the throttle valve; (4) Close the blowout preventer; (5) Try to close it tightly
Throttle valve; (6) Send a signal and quickly report to the team leader and technician; (7) Accurately record the column and casing pressure and mud increment
19. Downhole complexity during drilling
During drilling, due to improper selection of drilling fluid type and performance, poor wellbore quality and other reasons, the downhole is blocked and stuck, as well as serious jumping, lost circulation and blowout during drilling, which can not maintain the normal progress of normal drilling and other operations.
20. Drilling accident
It refers to the consequences of broken drilling tools, stuck drilling, blowout and fire caused by poor inspection, illegal operation, improper or negligent measures to deal with complex downhole conditions.
21. Lost circulation
Lost circulation is mainly found by the following phenomena: (1) the amount of drilling fluid pumped into the well is greater than the return amount, and there is inflow or outflow in serious cases; (2) The liquid level of drilling fluid tank decreases and the amount of drilling fluid decreases; (3) The pump pressure decreased significantly. The more serious the leakage, the more obvious the pump pressure drop
22. Sticking and causes
Sticking means that the drilling tool cannot move freely in the well for a long time due to geological factors, poor performance of drilling fluid and improper technical measures. This phenomenon is called sticking. It mainly includes sticking stuck drill, sand setting stuck drill, sand bridge stuck drill, well collapse stuck drill, reduced diameter stuck drill, mud bag stuck drill, falling object stuck drill and drilling tool falling off and stuck drill.
23. Methods for handling sticking accidents
(1) Oil soaking and unblocking; (2) Use a jar to shake the card; (3) Reverse thread sleeve milling; (4) Explosive loose buckle; (5)
Explosive drilling tools, sidetracking, new holes, etc.
24. Cementing
Cementing is to run a fixed size casing string into the well, inject cement slurry around it, and fix the casing on the well wall to avoid the collapse of the well wall. Its purpose is to seal complex formations such as loose, easy to collapse and easy to leak; Seal off oil, gas and water layers to prevent mutual leakage; Install wellhead and control oil and gas flow to facilitate drilling or production of oil and gas.
25. Shaft structure
Including: (1) casing layer of a well; (2) Diameter and running depth of casing in each layer; (3) Corresponding bit diameter and drilling depth of each layer of casing; (4) The cement return height outside each layer of casing, etc.
26. Casing string substructure
(1) Guide shoe: guide the casing into the well to avoid casing insertion or scraping the well wall; (2) Casing shoes: guide in
The drilling tool pulled out from the inside enters the casing; (3) Swirl nipple: make the cement slurry swirl up and back, which is conducive to replacing the slurry and improving the quality of cement injection; (4) Casing back pressure valve: prevent the backflow of cement slurry and prevent the slurry from entering the casing during casing running; (5) Supporting ring: supporting rubber plug and controlling the height of cement plug; (6) Casing centralizer: center the casing in the drilling to improve the cementing quality.
27. Cementing construction procedure Run the casing to the predetermined depth – install cement head, circulate mud and ground pipeline Apply isolating fluid – → inject cement → top rubber plug – → replace mud – + bump pressure → end of cement injection and wait for setting.
28. Well completion wellhead device
(1) Casing head — seal two layers of casing annulus, hang the second part of casing string and bear part of the weight;
(2) Tubing head – socket taper pipe hanger, connecting oil layer casing, Christmas tree, blowout gate and pipeline; (3) Oil extraction
Tree – control oil and gas flow, carry out production safely and planned, and carry out well completion test, liquid injection, well killing, oil well wax removal and other operations.
29. Liner cementing method
Liner cementing is a cementing method that only cementing the casing in the newly drilled open hole section in the lower part in the well with casing in the upper part. There are three fixing methods for tailpipe: tailpipe seat at the bottom of the well; Cement sheath Hanging method; Tail pipe hanger suspension method.
30. Oil test
After the oil and gas reservoir is found by drilling, it is also necessary to make the oil and gas flow in the oil and gas reservoir flow from the bottom of the well to the ground, and obtain the dynamic data such as oil and gas reservoir production and pressure, as well as the properties of oil, gas and water through testing, which is called oil test (gas).
31. Perforation
When drilling is completed, it is necessary to run the casing and inject cement to fix the well wall, and then run the incident perforator to shoot the casing and cement sheath until the oil (gas) layer is opened, so as to open the channel for oil and gas flow into the wellbore, which is called perforation. At present, there are two kinds of perforators widely used at home and abroad: Bullet perforator and shaped charge jet perforator.
32. Bottom hole pollution
Bottom hole pollution, also known as bottom hole damage, refers to the phenomenon that the formation permeability near the wellbore is reduced due to the leakage of drilling fluid or the filtrate of water-based drilling fluid into the formation during drilling or workover.
33. Induced spray
Before perforation, in order to prevent blowout accidents, oil and gas wells are generally filled with kill fluid. After perforation, in order to export the liquid in the formation to the ground, it is necessary to reduce the liquid column of the kill fluid and reduce the pressure on the fluid in the formation. This process is a – Procedure in oil testing, which is called induced injection. The induced injection methods include replacement injection method, suction method, bailing method, gas lift method, etc.
Drill pipe formation test
Drill pipe formation test is an advanced technology that uses drill pipe or tubing to run the formation tester with packer into the well for oil test. It can be tested not only in the well with casing, but also in the open hole well without casing; The test can be carried out either after drilling or in the middle of drilling.
35. Cable formation test
After the oil and gas display is found during drilling, the cable can be used to run into the formation tester to obtain the fluid sample in the formation and measure the formation pressure, which is called cable formation test. This test method is relatively simple and can be carried out many times and repeatedly.
36. Tubing transmission perforation
Tubing transmission perforation is an advanced technology in which the tubing brings the perforator underground. After perforation, the formation fluid can directly pass through the tubing and lead to the ground. It is not necessary to fill a large amount of kill fluid into the well during perforation to avoid bottom hole pollution.
37. Rock porosity
The porosity of rock refers to the ratio of the space volume VP not filled by solid material in rock to the total volume VB of rock. In Greek letters φ The expression is: φ= Vpore / V rock × 100%=Vp/Vb × 100%
38. Volume coefficient of formation crude oil
Formation crude oil volume coefficient β o. Also known as underground volume coefficient of crude oil, or crude oil volume coefficient for short. It is the ratio of the volume of crude oil underground (i.e. the volume of formation oil) to the volume after degassing on the ground. Underground volume coefficient of crude oil β O is always greater than 1.
39. Fluid saturation
The saturation of a fluid refers to the volume percentage of a fluid in the pores of reservoir rock. It indicates the extent to which the pore space is occupied by a fluid. If the pores of rock are filled with several phases of fluid, the sum of fluid saturation of these phases is 1 (100%).