Gtotal Btotal
As a general guideline, MDIP should not vary by more than - 0.3 degrees from the local magnetic dip angle or from survey to survey during a bit run. The local magnetic dip angle is determined by using magnetic modeling software or directly measuring it through infield referencing. Surveys which do not conform to this guideline should alert the field engineer that some magnetic interference or pipe movement is probable, or that there was a hardware failure. MDIP may also change abruptly from bit...
HDD Technology and Equipment
A basic horizontal-directional drill-rig is illustrated in Figure 3-1. Horizontal directional drilling is accomplished using a drill rig. It services a bottom-hole assembly BHA that is responsible for creating a curved bore hole. The BHA consists of a drilling tool that is capable of creating a curved bore hole and a guidance system that locates the bore hole and directs changes in the trajectory. There is a variety of HDD rigs currently in use. Table 1-3 lists the three general categories of...
Concepts of Petroleum Geology and Basic Rock Properties
Petroleum is not found in underground lakes or rivers, but it exists within the void space of certain rocks. Unfortunately, these oil-bearing rocks are a definite minority, and the determination of their whereabouts is the basic problem confronting geologists and geophysicists. The mechanism of the origin and accumulation of petroleum is not completely understood and is the subject of much controversy. However, a great deal has been learned about the habitat of oil and gas, i.e., the nature of...
Shear Rate RPM
Plastic Viscosity PV - Drilling muds are usually composed of a continuous fluid phase in which solids are dispersed. Plastic viscosity is that part of the resistance to flow caused by mechanical friction. The friction is caused by Viscosity of the fluid phase. For practical field applications, plastic viscosity is regarded as a guide to solids control. Plastic viscosity increases if the volume percent of solids increases, or if the volume percent remains constant, and the size of the particle...
API RPlb TB TG GSB Db
at the riser connector, allowing the riser tensioners to lift the riser clear of the stack. After disconnect, the vessel should be moved off the well location and guidelines slackened to prevent the heaving riser and LMRP from striking the BOP. If conditions permit, the riser and LMRP can be retrieved and stored on the vessel. Otherwise the riser should be raised as high as possible and hung off. 4.4.4.2 Emergency. Each rig should be equipped with written emergency disconnect procedures which...
Ice Drilling and Coring
Charles R. Bentley, Bruce R. Koci, LaurentJ.-M. Augustin, Robin J. Bolsey, James A. Green, Jay D. Kyne, Donald A. Lebar, William P. Mason, Alexander J. Shturmakov, Hermann F. Engelhardt, William D. Harrison, Michael H. Hecht, and Victor Zagorodnov 4.2.1 Surface-Driven Rotary Drills 224 4.2.3 Cable-Suspended Electromechanical Drills 226 4.2.4 Cable-Suspended Electrothermal Drills 248 4.2.6 Koci Drill for Debris-Laden Ice 259 4.3.1 Hot-Water Drilling Systems 262 4.3.5 Electrochaude 284 4.3.6...
Constant Bhp Kill Methods
There are three 'constant bottom-hole pressure' kill methods in common use today which are Wait amp Weight Method also known as the 'Engineer's Method' These three techniques are very similar in principle, and differ only in respect of when kill mud is pumped down. In the Driller's method, the kill is split into two circulations. During the first, the kick fluid is circulated without changing the mud weight once the kick is out, the mud is weighted up and pumped around the well on the second...
Tapered Spindle Grinder
For shallow and small diameter holes up to 6 inches in depth, use the tapered spindle internal grinder. Tapers may also be ground on the work by using either the taper attachment or the compound rest. See Figure 9-40. The deep-hole grinder with the extended housing offers a rigid precision grinder for holes as deep as 18 inches. Tapers may also be ground with the deep-hole grinder. See Figure 941. The Versa-Mil external grinder with the wheel guard removed may be used for internal grinding of...
Stability and Moving
Stability is simply the ability of a rig to remain afloat. The subject of stability is further divided under the two headings of a Intact Stability and b Damaged Stability. For every rig, the designer or builder should furnish the rig owner with a Stability Booklet which, at a very minimum, should contain a Hydrostatic Properties , b Cross Curves of Stability, c Statical Stability Curves, and d Dynamic Stability Curves, Items c and d should be sufficient to cover the normal operating range of...
Chapter Footnotes 1
1 Geotechnical Engineers Handbook, Robert W. Day, McGraw-Hill, 2000 2 Horizontal Directional Drilling, Good Practices Guidelines, HDD Consortium, May 2001 3 J. D. Hair amp Associates, Louis J. Capozzoli amp Associates, and Stress Engineering Services 1995 . Installation of Pipelines by Horizontal Directional Drilling, An Engineering Design Guide, prepared for the Offshore and Onshore Design Applications Supervisory Committee of the Pipeline Research Committee.
Multiple wells from offshore structures
The most common application of directional drilling techniques is in offshore drilling. Many oil and gas deposits are situated well beyond the reach of land based rigs. Drilling a large number of vertical wells from individual platforms is both impractical and uneconomical. The obvious approach for a large oilfield is to install a fixed platform on the seabed, from which many directional boreholes can be drilled. The bottomhole locations of these wells are carefully spaced for optimum recovery....
Gravity Toolface
Gravity toolface is the angular distance the bent sub scribe line is turned, about the tool axis, relative to the high side of the hole Gravity toolface Dir Probe Gravity Toolface Toolface Offset If the inclination of the wellbore is above 5 to 8 , then gravity toolface can be used The toolface will be referenced to the highside of the survey instrument, no matter what the hole direction of the survey instrument is at the time The toolface will be presented in a number of degrees either right...
Additional ReviewReading Material
EXLOG, MS-3026 Theory And Applications Of Drilling Fluid Hydraulics Baker Hughes INTEQ, Drilling Fluids Manual, 1991 API, The Rheology of Oil-Well Drilling Fluids, Bulletin 13D,2nd Edition, May 1985 API, Recommended Practice for Drilling Mud Report Form, Report 13G, 2nd Edition, May 1982 Chilingarian, G.V. and Vorabutr, P., Drilling and Drilling Fluids, Elsevier Science Publishers, 1983 Bourgoyne Jr., Adam, et al Applied Drilling Engineering, SPE Textbook Series, Vol. 2, 1986 Moore, Preston...
Gamma Ray Applications
Determining shale volume - By using the relative response of the gamma curve compared with a 100 shale reading, the shale volume Vsh in the formation can be estimated from the following equation To calculate the shale volume Vsh of any zone, determine the denominator of the equation by subtracting the clean sand reading GRclean from the shale baseline reading GRsh . Then, determine the numerator of the equation by subtracting the reading in the zone of interest GRzone from the shale baseline...
Survey Accuracy As A Function Of Inclination
Berror IS A LARGER PERCENTAGE OF Bref AT HIGHER INCLINATIONS For systematic uncertainty, the uncertainty is along the Z-axis. This will result in decreased survey accuracy when drilling east or west as opposed to drilling north or south. This is due to the fact that Berror will tend to pull Bref in the direction of the Z-axis, away from Bn. This relationship is shown in the figure below.
Control Fluid Circuit
In addition to the control fluid circuits used to operate stack functions such as ram or annular preventers, the control system must also perform other functions such as control of subsea regulators, provide readback pressures, latch unlatch the subsea control pods and charge the subsea accumulators. Fig 9.4 shows a typical control fluid circuit. The hydraulic fluid is mixed, pressurised and stored in accumulator bottles by the hydraulic power unit. A pilot operated accumulator isolator valve...
Bop Stack Equipment
Floating drilling rigs may be equipped with either a 'one stack' or a 'two stack' BOP system. The two stack system is a combination of a 2,000 or 3,000psi large bore stack and a 5,000, 10,000 or 15,000psi stack. A one stack system is either a 10,000 or 15,000psi system. The following list gives the common sizes and various configurations 183 4 - 10,000 and 15,000psi WP 163 4 - 10,000 and 15,000psi WP 135 s - 5,000, 10,000 and 15,000psi WP 4 rams and 2 annulars 4 rams and 1 annular 3 rams and 1...
Automatic Opening To Diverter Lines As Bag Closes 1
Figure 6.3.3 Example diverter with annular packing element Figure 6.3.3 Example diverter with annular packing element Figure 6.3.4 Example diverter with insert - type packer Figure 6.3.4 Example diverter with insert - type packer Figure 6.3.5 Example diverter with rotating stripper Figure 6.3.5 Example diverter with rotating stripper Figure 6.3.6 Example diverter systems - Integral sequencing Figure 6.3.6 Example diverter systems - Integral sequencing
Cuttings Bed Suppression
Cuttings beds formation in deviated holes can be suppressed by using muds with exceptionally good suspension characteristics. However, high flow rates are still necessary since the beds can never be totally eliminated. For water based mud, the best conventional additive for this purpose is XC polymer. All the major service companies now offer low shear enhancers sometimes referred to as rheology modifiers for oil based muds. A simple force balance approach can be used to determine the minimum...
Pump Rate
The single most crucial factor for successful hole cleaning is mud flow rate, especially for deviated holes. As a rough guide, the annular velocity needed for cleaning wells deviated 50 - 60 is approximately twice that required for the vertical case. Take all reasonable steps to reduce frictional pressure. Doing so will extend the range of available flowrate. In critical cases, careful consideration should be given to BHA design, nozzle selection, and additional losses due to mud motors MWD...
The basic ingredient of calcium chloridecalcium bromide brines
CaCl2 CaBr2 is a calcium bromide solution that ranges in density from 14.1 to 14.3 ppg 1.72 SG the pH range is 7.0 to 7.5. The density of CaBr2 brine can be increased by adding calcium chloride pellets or flakes. However, a 1.81 S.G. CaCl2 CaBr2 solution crystallizes at approximately 65 F 18 C . CaCl2 CaBr2 brine can be diluted by adding a CaCl2 brine weighing 11.6 ppg 1.39 SG . The corrosion rate for CaCl2 CaBr2 is no more than5 mm per year on N-80 steel coupons at 300 F 149 C . If a...
Chemical Analysis Mud Check
Table 6 pH of 10 Solution approximate Soda Ash Sodium Hydroxide Potassium Hydroxide Calcium Hydroxide Barium Carbonate Gypsum Alkalinity of the whole mud, or PM, is a measure of both the soluble and insoluble materials in a mud. Soluble ions, such as hydroxyls, carbonates and bicarbonates, and insoluble compounds, such as lime and magnesium hydroxide, have an affect on the PM. The PM is expressed as the volume in cm3 of 0.02N sulfuric acid required to lower the pH of 1 cm3 of the mud to 8.3....
Redundancy
The two subsea control pods are functionally identical. When a pilot control valve rams close for example is operated on the hydraulic control manifold a pilot signal is sent down both umbilicals so that the associated SPM valve in each pod 'fires'. If the pod selector valve is set on yellow then power fluid is sent only to this pod and it is only through the SPM valve in this pod that the fluid will reach the ram operating piston. The pod selection has no effect on the pilot system. Once the...
Removal Section
Undesirable drilled solids and gas are removed in this section before new additions are made to the fluid system. Drilled solids create poor fluid properties and cause many of the costly problems associated with drilling wells. Excessive drilled solids can cause stuck drill pipe, bad primary cement jobs, or high surge and swab pressures, which can result in lost circulation and or well-control problems. Each well and each type of drilling fluid has a different tolerance for drilled solids. Each...
Hopkin S Particle Slip Velocity Chart
An example problem follows Hopkins slip velocity chart. Hopkin ran over 2,000 dynamic particle lifting tests with a 8 foot long 4.5 diameter vertical tube with 13 types of mud and 52 particle shapes and sizes. The particles were circulated from the bottom of the tube to the top with the fluid in laminar, transitional, and turbulent flow. Mud Marsh funnel viscosities ranged from 26 to 1,000 seconds qt. A minimum of three data points were collected for each test. A curve fit of his graph not...
What Are Gamma Rays
Gamma rays are a form of high energy electromagnetic EM radiation. Other examples of EM radiation are visible light, radio and microwaves, infrared and ultraviolet light, and x-rays. Each of these forms is distinguished in the EM spectrum by their frequency f and wavelength A, . In free space that is, a vacuum all EM waves travel at the speed of light, c, which is 3 108 meters second, or 186,000 miles second The frequency and wavelength are related to the speed by the equation While the...
Drilling Hole
1 Run a 17 2 bit and BHA. Drill out the 20 float collar, cement, casing shoe and wash down to the rat hole TD. If it is planned to drill a long section, install a well head bore hole protector into the base flange. 2 Drill 5m 15ft of new hole, condition the mud and perform a leak off test Refer to section 11 . 3 Resume drilling with the 17 2 bit using the proper BHA for either a vertical or deviated hole Refer to section 8.1 . 4 Drill the 17 2 hole down to KOP if in a deviated hole phase and...
Drilling Hole 1
1 Run a 12 4 bit and BHA. Drill out the 17 2 float collar, cement, casing shoe and wash down to the rat hole TD. If it is planned to drill a long section, install a wellhead bore hole protector into the first casing spool. 2 Drill 5m 15ft of new hole, condition the mud and perform a leak off test Refer to section 11 . 3 Resume drilling with the 12 4 bit using the proper BHA for a vertical or deviated hole. 4 Drill the 12 4 hole down to KOP and, if in a deviated hole phase, change the BHA for...
Workbook
Figure 5-15 Type 1 Build and Hold Figure 5-15 Type 1 Build and Hold Build-up section which may have more than one build up rate Tangent section Deep wells with large horizontal displacements Moderately deep wells with moderate horizontal displacement, where intermediate casing is not required Features There are several variations Shallow KOP - Build, hold amp drop back to vertical Build-up section - Build, hold, drop amp hold illustrated above Tangent section - Build, hold amp continuous drop...
Marine deltas
The mouths of rivers fall into two general categories. A river with a low sediment load may reach the sea in an estuary, where the effect of current, waves, and tides keeps sediment from accumulating. A heavily laden river, however, usually creates a marine delta, a seaward extension of land at or near sea level caused by the accumulation of sediments at the river's mouth. A delta is composed mostly of sediments brought down by the river, but mixed with them are fine wave-borne sediments...
Plug Choices and Techniques
When a loss zone cannot be stabilized with sealing materials it may be desirable to try a plug. Several choices and techniques are available however, in all cases a reasonably accurate estimate of depth of the loss is required prior to setting the plug. Spinner surveys, radioactive traces, and temperature surveys are most commonly used for this purpose. The following is a typical list of plug choices. These are generally classified as soft, medium or hard plugs Bentonite-diesel oil squeeze gunk...
Clear Brine Fluids SolidsFree Brine Fluid Systems
These fluids are made from fresh water or are solutions made with water and the addition of one or more electrolytes. These fluids do not contain either suspended particles or viscosifiers, which means neither filtration control nor viscosity control are provided. Some brines are corrosive and when corrosion inhibitors are required, compatibility studies should be performed. Some brines are toxic and precautions should be taken to prevent contact with unprotected skin. Brine solutions can be...
Principles of Neutron Logging
Neutrons are emitted from the source at a high energy, usually between 1 and 10 MeV. However, they are not detected until their energy has been reduced to a fraction of an eV through collisions with atomic nuclei in the formation. The rate at which energy is lost by the neutrons is a function of the elements in formation. Hydrogen is the most efficient element in slowing down, or moderating, neutrons. Porosity is inferred from the detection of these low energy, or thermal, neutrons because...
Balance Of Pressures
Once the well is shut-in providing nothing has broken down, the pressures in the well will be in balance. What is lacking in hydrostatic head of fluid in the well is now being made up by surface applied pressure on the annulus and on the drill pipe. Providing the bit is on bottom and the string is full with a known mud density this allows us to determine what the formation pressure is and hence what kill mud weight is required to achieve balance. On the drill pipe side of the U-tube. Figure 5.1...
Chronology Of Submersible Rigs
CHRONOLOGY OF JACKUP RIGS, 1953-1969 In 1955, the first 3-legged jack-up appeared on the scene Figure 1-6 . The rig was the R. G. LeTourneau jack-up, the Scorpion, for Zapata Offshore Company. The Scorpion, an independent leg jack-up, used a rack and pinion elevating system on a truss framed leg. The rig worked very successfully for several years but was lost during a move in the Gulf of Mexico. The Scorpion was closely followed by The Offshore Company Rig No. 54. For Rig No. 54, however, a...
Piping and Equipment Arrangement
Drilling fluid should be processed through the solids-removal equipment in a sequential manner. The most common problem on drilling rigs is improper fluid routing, which causes some drilling fluid to bypass the sequential arrangement of solids-removal equipment. When a substantial amount of drilling fluid bypasses a piece or pieces of solids-removal equipment, many of the drilled solids cannot be removed. Factors that contribute to inadequate fluid routing include ill-advised manifolding of...
Multiple Well Man foldProduction Station
The station consists of three basic hardware components the base, the wellhead connector assembly, and the subsea work enclosure. It also includes a number of associated supporting subsystems. A full-scale prototype has been constructed and tested. The prototype base Figure 4-6 is composed of structural piping and is about 50 feet square, 26 feet high. It weighs approximately 140 tons in air, with positive buoyancy in water with pipes unflooded. A circular base was designed to serve as a...
Casing Check List
Within a reasonable time prior to the beginning of the casing operation, the Company Drilling and Completion Supervisor and the Drilling Contractor's Toolpusher shall physically check the availability on the rig of all materials necessary to operations. The following check list may be used as a guideline. a Casing joints, enough for planned depth with 5-10 excess or a min. of 10 joints. b Float equipment float shoe, float collar, stage collar back-up are recommended . e Solvent to clean casing...
The Drillers Method
In the Driller's Method, the kick is circulated out of the hole using the existing mud weight. The mud weight is then raised to the required level and circulated around the well. Two complete circulations are thus required, as a minimum, for this method. Since it deals separately with the removal of the kick and the addition of kill weight mud, it is generally considered to be the simplest of well control methods, and it requires least arithmetic. However, this results, in the well being...
Marsh Funnel Viscosity
Marsh Funnel viscosity is used to indicate relative mud consistency or thickness. Marsh Funnel viscosity is the time required seconds for a quart of mud to flow through a 2-in. long, 3 16-in. diameter tube at the bottom of the Marsh Funnel. This viscosity measurement is used to periodically report mud consistency. One quart of water should flow through a Marsh Funnel in 26 1. Hold one finger over the orifice at the tip of the funnel. Pour the mud sample through the funnel screen until mud...
Engine Control Instrument 1
Fig. 6.23. Aerated mud system. After Bobo, Ormsby, and Houch,42 courtesy Oil and Gas Journal. 2 greater safety quick weight buildup is quickly obtained by shutting off the injected air. Explosions and or fire possibilities are minimized by the water in the mixture. A typical layout for this method is shown in Figure 6.23. Air is injected into the system between the mud pumps and the standpipe. The air-mud ratio may be controlled by increasing or reducing inputs of each fluid. Such a system is...
Typical Properties of Saturated Salt Muds
Saturated Salt Muds typically exhibit high yield point values and gel strengths. Gel strengths, although high, are generally fragile. Table 21 lists typical properties for unweighted 10.5 lb gal and weighted saturated salt muds. Typical Properties of Saturated Salt Muds
Saturated Salt Muds
common practice to maintain the pH of the mud from 11-11.5 with additions of caustic soda. Saturated salt muds require larger additions of caustic soda to maintain a higher pH than do freshwater muds. Maintaining an 11 to 11.5 pH offers several advantages Deflocculants are more effective Lower concentrations of filtration control additives are required when Ca and Mg solubility is reduced Foaming tendency is lessened Mud is generally more stable Saturated salt muds will normally contain soluble...
Secondary ram shaft seal
1 Manual-lock piston in open position Locking shaft 2 Manual-lock piston in closed and locked position Locking shaft 2 Manual-lock piston in closed and locked position 2 Poslock piston in closed position 3 Manual-lock piston in closed position 3 Manual-lock piston in closed position
Junk in the Borehole
Junk is a foreign object in the borehole, which is not meant to be there. Since the clearance between casing and collars stabilizers is not great, even a small piece of junk can stick the drillstring. Preventive measures include 1. Ensure downhole tools are in good condition 2. Inspect downhole tools regularly 3. Be careful when working around the rotary table 4. Leave the hole covered when the drillstring is out of the borehole 5. Install drillpipe wipers whenever possible If junk sticking is...
Shear Rate
Non-Newtonian fluids are classified into four major categories Those with properties independent of time, Those with properties dependent on time, The first two categories are of principal concern to drilling fluids. There is a further subdividing of these Time Independent, Non-Newtonian Fluids Time Dependent, Non-Newtonian Fluids
Bullheading
This is defined as pumping fluid into the well without circulation back to the surface. The fluid can be pumped down the drillpipe, down the annulus, or both. In most instances this will result in formation fracturing. This will occur at the weakest point, which is usually the formation near the last casing shoe. Obviously, in underground blowouts or wells with lost circulation, bullheading can prove useful since the fracture or loss zone already exists. Wells with short open hole sections and...
Soft Shutin Procedure While Tripping Fixed Rig
1 When a possible sign is observed, set top tool joint in the slips. 2 Install a full opening Safety valve on the drill pipe. Close the valve once it is installed. 3 Pick pipe up, check for flow. Check trip volumes. 4 OPEN choke line valve at Bop stack. HCR valve . 6 CLOSE choke. If this is not a positive shut-off type, it is necessary to close a valve just downstream of the choke in order to read well pressures. 8 Stab IBOP Grey Valve and open full opening safety valve. 9 Read and record...
Baker Hughes INTEQ Jwz
7. Determine what specifications govern the writing There is an FWR format and it usually uses a canned selection of questions statements which are to be answered. 8. Determine deadlines for each stage of the writing task Normally, rough drafts of the FWR are required after each casing point and at the end of the well. These deadlines also include when the final version of the report is due, when the illustrations or plots prints are due, and when all are to be delivered to the client. 9....