Preventing Stuck Pipe
If the driller is unable to free the stuck pipe or the force necessary to free the pipe is greater than the force that can be applied by the blocks, then other remedial measures must be used. Normally a lubricating fluid is spotted in the troublesome area and is used to dissolve the filter cake. Spotting procedures and calculations have been mentioned in the Advanced Logging Procedures manual, under Additional Volume Calculations. These spotting procedures are facilitated by pin-pointing the...
Oil And Mud Coating 1
DECK DRAINS TO COMMON HEADER EMPTY INTO SLOT ENGINE GENERATOR SET Fig. 5.15. Inland water drilling barge with heavy duty diesel-electric rig. After Rowan,10 Fig. 5.15. Inland water drilling barge with heavy duty diesel-electric rig. After Rowan,10 are available however, all are essentially valves designed for closing the annular passage between two concentric pipes. Most blowout preventers are either hydraulically or pneumatically operated, with manual operation available as a safety...
Results
Using the capability of the software to save in different formats, a drill was generated and exported into Abaqus and DEFORM using the SAT and STL formats, respectively. The drills were then meshed using the meshing module of these two packages. The resultant meshes along with the original solid model can be seen in Figure 4.14. Figure 4.14 Solid Model left , Meshed in Abaqus middle , and Meshed in DEFORM right . Figure 4.14 Solid Model left , Meshed in Abaqus middle , and Meshed in DEFORM...
Gel Strengthlbs ft secmin
This is a measurement that denotes the thixotropic properties of the mud and is a measurement of the attractive forces of the mud while at rest or under static conditions. As this and yield point are both measures of flocculation, they will tend to increase and decrease together, however a low yield point does not necessarily mean 0 0 gels Gel strength is measured with the viscometer by stirring the mud at high speeds for about 15 seconds and then turning the viscometer off or putting it into...
Selection Of Shale Shakers
The first consideration in selecting a shale shaker is to decide whether or not a gumbo slide, or gumbo-removal device, will be needed. This is often necessary when drilling recent sediments. A scalping shaker must be considered next. Scalping shakers are usually needed when large quantities of drilled solids or gumbo reach the surface. Usually, long intervals of 17 y-in.-diameter holes, with flow rates above 1000 gpm, require scalping shakers in front of fine mesh screens see Chapter 7 . The...
Presurvey Checklist For Magnetic Single Shots
An OpCo representative should ensure that the following is carried out. 1. Check that the required length of NMDC is available. 2. Check that the instrumentlanding assembly will seat correctly in the landing ring TOTCO ring , and will not jam or land eccentrically. 3. Check whether the instrument is to be top or bottom landed or used with a mule shoe. 4. Install the landing ring in the proper place when making up the BHA. Avoid landing the instrument directly on top of bit, mudmotor or turbine....
Freeing stuck pipe
When the drillstring becomes stuck, immediate action will prove to be most effective in most cases. Prior to taking this action, the cause of the problem must be determined. This is achieved by considering the circumstances leading up to getting stuck and relating this to well conditions and history. Pipe will be stuck, either mechanically, or differentially. Sometimes, mechanically stuck pipe will end up differentially stuck too, but even in the worst hole, this will take time. 3.3.1...
Specific Gravity
The density of any material is derived by multiplying the specific gravity of that material by the density of pure water. For example, the specific gravity of barite is 4.2 and its density is equal to 4.2 8.33 lb gal 35 lb gal. Conversely, to convert from density to specific gravity, divide the density of a material or mud by the density of pure water. As an example, a 17.5 lb gal mud has a specific gravity of 2.1. To determine the weight of 1 bbl of barite, determine the density of 1 bbl of...
Junk Baskets
Many types of junk baskets exist. The three categories are the plain, the reverse circulating, and the pump junk baskets. The operation of the plain junk basket is to run into the hole, circulate, cut a short core to push the object into the barrel of the junk basket, grasp the core and or object with the fingers or grapple of the junk basket. The pipe is usually chained out of the hole not rotated to prevent the dropping of a partially grapped object. Reverse circulating junk baskets are the...
Nozzle Areasqin 1
Fig. 7.8. Pressure drop across conventional water course bits. Assuming pm 9.5 lb gal and C 0.80. Courtesy Hughes Tool Company. where n either plastic or apparent mud viscosity nw water viscosity T temperature, F Use of this equation requires knowledge of viscosity at two temperatures, so that linear plots can be established. Water viscosity data were given in Figure 6.8. Yield point at the desired temperature may then be calculated from Eq. 6.4. The average circulating temperature of the mud...
Chapter Footnotes Cfm
1 Jeffery S. Puckett, PE 2000 . Analysis of Theoretical Versus Actual HDD Pulling Loads. Bending Stress stress bending stress bending 13342psi External Hoop Stress stress hoopexternai stress hoopextemai 470.6psi Thermal Stress k .0000065 Tt 80 T2 50 stress thermal Bk Combined stress and limitations Combined stress is analyzed by calculating the maximum shear stress on a small element In the pipeline. The maximum shear stress should be limited to 45 of he SMYS ASME ANSI B31.4 . The maximum shear...
Systematic And Random Errors
Wolff and deWardt published the following table which presents their finding in the study of surveying errors in the North Sea area. They also wrote that surveying errors are more systematic rather than random. At the time they worked for Shell
Undergauge Borehole
When drilling long sections of abrasive formations, the gauge protection on the bit and stabilizers can become so worn it becomes ineffective. Any additional hole that is drilled will be undergauge. Preventive measures include 1. Properly gauge the bit and stabilizers after each run 2. Ream back to bottom if an undergauge hole is suspected 3. Never force a new bit to bottom 4. Select bits with good gauge protection 5 amp 7 feature in roller 5. Carefully run fixed cutter bits after roller cone...
Cost Per Foot Calculations Including Downhole Motors
When downhole motors are used and charged at an hourly rate, they can be included in the cost equation C CRig D tf CBit Moto D C d The following example is a case history. The above equation was used to qualify the savings to an operator in the North Sea when drilling a very hard conglomerate formation with an impregnated diamond bit and a turbine. Calculations were made based on all the bit runs through the conglomerate formation on five different wells. The following values were used for the...
Flowline Pullin
The unique LPS diverless flow-line pull-in system is a significant part of the entire program as flow-line installation is usually expensive and subsea connections normally require diver assistance. As pointed out earlier, the original flow-line connection for Shell Oil Company wets accomplished using a preformed line with external TFL loops pulled by a winch within the service capsule. With the horizontal wellhead cellar design, the flow line approaches the cellar from the ocean floor and is...
Final Refusal Depth
The following procedure details the determination of final refusal depth. 1 When the driving depth of the conductor pipe is not specified in the Drilling Programme, the final depth of the driving is the 'refusal depth'. The refusal value generally used is 1,000-1,100 blows metre. Local experience could dictate a different refusal value. The driving depth can be predetermined by conducting soil boring analysis. Examine offset well data for depths and potential problems in order to determine if...
Appendix A Glossary
Accumulator BOP . A pressure vessel charged with gas nitrogen over liquid and used to store hydraulic fluid under pressure for operation of blowout preventers. Accumulator Riser Tensioner . A pressure vessel charged with gas nitrogen generally over liquid that is pressurized on the gas side from the tensioner high-pressure gas supply bottles and supplies high pressure hydraulic fluid to energize the riser tensioner cylinder. Actuator. A mechanism for the remote or automatic operation of a valve...
Jetting Assemblies
A typical jetting assembly used to drill a 12 74pilot hole is This is essentially a strong angle build rotary assembly with a suitable bit for jetting. The upper stabilizer is optional and is often omitted.
Environmental Considerations For Drilling Operations
11.3 Environmental Regulations 571 11.4 Site Assessment and Construction 575 11.4.3 Drilling Fluid Considerations 578 11.5 Environmental Concerns While in Operation 583 11.5.4 Reclamation of the Drill Site 589 11.5.7 Fixation of Reserve Pit Water and Solids 592
Screen Deck Design
Hook-strip screens have been mounted with both underslung and over-slung supports. Some previous generations of oilfield shaker designs used screens that were underslung, or pulled up from the bottom of a group of support, or bucker, bars Figure 7.15 . These support bars would divide the flow of material down the screen. Some problem is experienced occasionally when solids are trapped under the rubber bar supports. Some linear motion shale shakers utilize overslung screens Figure 7.16 . With...
Placement
The stabilizer is most commonly run directly above the motor. According to the 3-point geometry, increasing L by moving the first string stabilizer higher in the BHA reduces the Theoretical Geometric Dogleg Severity. This does not always work in practice. It has been found that moving the stabilizer higher can make it harder to get away from vertical in a kick-off. However, once some inclination has been achieved, the rate of build is often greater than the TGDS. For flat turns or for dropping...
Gas Migration When Gas In Solution
Well Control problems can result in blowouts because of the solubility of certain gases in specific types of mud e.g. Methane dissolves in oil base mud, and S dissolves in water base mud. This fact makes it more difficult to detect a kick. A large gas influx entering the wellbore may change the pit level very little if the gas dissolves in the mud. The influx is then circulated up the wellbore in the mud column, until the hydrostatic pressure on top of the gas decreases to a certain point then...
Biopolymers
Recently several biopolymer X-C Polymer, Rhodopol, Enerflo, Drillam X 84 have found worldwide application in drilling fluids. These polymers are quite expensive. When used in concentrations as low as 2-3 kg m 3 1 Ib bbl a major increase in YP and gel values is normaly obtained. Various salts sodium chloride, magnesium chloride and pottassium chloride are used for drilling through salt sections. The mud is saturated to the salt that is expected in the hole and thus washouts due to the...
Diamond Gauge Protection 1
Typical Part Section through Centre of Bit Typical Part Section through Centre of Bit with Diamonds Low Pressure Collectors with Diamonds Low Pressure Collectors
MakeUp Torque
Part of the strength of the drillstring and the seal for the fluid conduit are both contained in the tool joints. It is very important therefore, that the correct make-up torque is applied to the tool joints. If a tool joint is not torqued enough, bending between the box and pin could cause premature failure. Also, the shoulder seal may not be properly seated, resulting in mud leaking through the tool joint, causing a washout. Exceeding the torsional yield strength of the connection by applying...
Toof Face
Azimuth is the direction of the wellbore relative to true or grid north in the horizontal plane. We measure this angle by measuring the direction of the earth's magnetic field relative to the tool. Magnetic Declination is the difference in degrees between magnetic north and true north or grid north for a particular location on the earth. This value changes with time and location and must be determined using the software program. On a directional well it is important that the value for magnetic...
Circulation Prior to Tripping
Hole size and inclination will influence the minimum off-bottom circulation time prior to tripping. The figures in the table below are guidelines based on simple slip velocity considerations and field experience. In practice, some of the section back to surface will not be deviated at the same angle. The overall minimum circulation time prior to tripping should be apportioned in direct relation to the relative lengths of section at each angle. This is shown in Figure 25 for tripping out of 445...
a Diverter System
The subsea diverter system is an integral part of the marine riser system. Diverter mechanism consists primarily of a packing insert that can seal on drill pipe or open hole with an insert plug , a control system, two flow lines, a ball joint and valving. The Regan Hughes Offshore KFD diverter is the most common system used on today's rigs. There are three basic models KFDG Gimble which is used on rigs that do not have an upper ball joint. KFDH Housing used on many vessels having limited room...
AdvantagesDisadvantages of NonDispersed Polymer Muds
Advantages Disadvantages of Polymer Muds Irreversible adsorption of the polymer on clays Easily converted to a deflocculated system Requires more dilution than deflocculated systems More corrosive than deflocculated systems Sensitive to contaminants carbonate contamination difficult to treat Contamination - Non-Dispersed Polymer Muds Contaminant Treating of Non-Dispersed Polymer Muds Increasing retort solids, PV, YP, gels, MBT. Thick mud on bot-toms-up after trips. High flowline viscosity....
Cement bond logs CBLVDL
Cement bond logs are sonic tools which emit sounds and pick up reflections. They are used inside casing as a means of locating the top and the quality of cement behind the casing. Uncemented casing resembles a tubular bell and transmits sound easily. Well-cemented casing will dampen sound vibrations and produce different results which can be interpreted together with well data. The value of CBL VDL is debatable. The author has seen apparently uncemented casing behind which communication was...
Example Lock Up
In the example problem on drag of the components of the drill string, it was computed that the expected drag from the BHA, the drillpipe in the reach, in the lower build, and the tangent section was 14,853 lb. The available gravity weight for the bit for that same section of drillpipe was computed to be 1,761. In the above example it was learned that the resistance to buckling of 5 drillpipe for the conditions of that example was 24,204 lb. Thus, the maximum weight which can be placed on the...
Beach sand
The linear zone of sediments marking a former coastline may form a series of sandstone reservoirs. Unlike river sandbars, grain orientation and direction of maximum permeability are across the trend. Information on facies changes is especially useful in locating this type of reservoir. Knowing that limestone and shale usually form some distance offshore, the geologist can determine the direction in which the sediments become coarser and more permeable. The coarsest, best-sorted, most permeable...
Applying a West Declination
If the magnetic direction is 120 and the declination is 5 west , the true direction would be calculated as True Direction Magnetic Direction Declination Implications of an Incorrect Declination Since declination is a addition of degrees of correction to the magnetic hole direction, any mistakes made to the declination have serious consequences. For example, if you intend to apply a 18 declination but instead input a -18 declination, your reported hole direction will be wrong by 36 This can...
Measurementswhiledrilling Mwd
MWD systems allow the following variables to be measured The purpose of these logs is explained on page 164. The range of services provided by MWD are improving and the rate of change is accelerating. If the present rate of development continues, then MWD could effectively replace electric logging for many evaluation applications in the near future,
degree Gyro Compass
Read from the 0 vernier line horizontally to the intersection of the inclination to determine the inclination to a precision of 0.5 30 always round down Use the 30' vernier scale to increase the precision of the reading to 5'. To use the vernier, look for an alignment of the division markings on both the vernier and inclination scales, read the value on the vernier scale at this intersection point. This is then added to the previous reading Determine the hole direction of the chart as follows...
Example Drillpipe Tension
The weight indicator shows 230,000 lbs. The block and lines weight 30,000 lbs. A pump pressure gauge in line with the drillpipe shows 7,000 psi. The drillpipe is 5 by 4.276 by 19.5 ppf and the average weight per foot of the steel in the drillpipe is 21.4 lb ft. What is the real tension in the drillpipe at the rotary table and at a depth of5,000 feet The inside end area of 5 drillpipe 0c 4 4.2762 14.360 sq. in. Treal 230,000 - 30,000 7,000 14.360 300,520 lb rotary table Treal 300,520 - 21.4...
Annular Velocity 1
What is the annular velocity at 110 SPM on one pump, opposite a. Drill Collars Open Hole AV0h dc _ft min b. Drill Pipe Open Hole AV0H DP _ft min c. Drill Pipe Casing AVCSG DP _ft min The annular velocity defines the average velocity at which the mud passes through a specific annular space and is normally expressed in units of ft min. The following annular velocities opposite specific intervals will be based on pump output at 110 SPM and 94 volumetric efficiency. a. Drill Collars Open Hole, AV0h...
Mike Hughes and Larry Cushman
Diving can be defined as a method of transportation that allows a man to perform work in the ocean, or on the ocean floor. There are two basic ways men can work underwater. The first is pressurized or hyperbaric diving. With this method the man goes directly into the ocean, and is therefore continuously subjected to the increasing pressures of depth. The second method of diving is unpressurized or isobaric diving in which the man goes under water in an unpressurized sealed diving bell,...
Pump Output
What is the pump output Q in barrels per stroke bbl STK and gallons per stroke gal STK at 94 volumetric efficiency A National 10-P-130 which has a 10-in. stroke with a 5-1 2 in. liner at 100 volumetric efficiency will deliver 3.0996 gal STK. Triplex Single Acting Mud Pump Capacities Per Cycle Barrels per Stroke -100 Volumetric Efficiency Duplex Double-Acting Mud Pump Capacities Per Cycle Barrels per Revolution - 90 Volume Efficiency - Rods Deducted Therefore, at 94 volumetric efficiency a....
aAnnular to Ram Stripping
When stripping with ram preventers, the same principle applies to packing element wear as the annular preventers. The lower the closing pressure while stripping, the longer the life of the sealing element. Initially CLOSE the ram preventers, using 1500 psi pressure, and then adjust the regulator to reduce the pressure, depending on the pressure of the well. The annular preventer should also be closed with 1500 psi and the regulator adjusted to sealing pressure with a minimum of 600 psi.
Density Control of Water Soluble Completion Fluids
The concept of a water soluble fluid consisting of a saturated brine and ground salt NaCl in combination with polymeric viscosifiers and filtration control agents has been patented by TBC-BRINADD and licensed by a number of workover completion fluid suppliers. In these systems, the ground salt functions as a weighting agent. Figure 5 gives a typical particle size distribution for a ground salt weighting agent. Due to the 2.18 specific gravity, the typical density range for these formulations is...
Austin Chalk Well Dimmit County Texas Usa
The following is a description of the typical Austin Chalk well in Dimmit county, Texas. Vertical wells in the area produced from no oil to 5 barrels of oil per day. The described well initially flowed 1,660 bopd. The Austin Chalk is a highly, vertically fractured formation with no matrix permeability. The horizontal section of the well was drilled under balanced in order to assess the production rate as the well was drilled and to reduce plugging of fractures with drill solids. The 7 5 8...
List Of Abbreviations
Hmud Head of Mud or Hydrostatic Pressure of Mud usually psi . Gmud Pressure gradient of mud usually psi foot . PF Formation Fluid Pressure usually psi . PFB Formation Breakdown Pressure or Formation Fracture Pressure or Formation Breakdown Pressure Gradient usually psi foot . Maximum Equivalent Mud Weight, to produce Formation Breakdown Pressure at Shoe. Maximum Allowable Annular Surface Pressure usually psi . Surface Pressure, which if exceeded may cause leakage of whole mud into formation of...
Bit Technology 1
The Advanced Logging Procedures workbook contains information on drill bits, IADC classifications and bit grading, and should be reviewed before beginning this chapter. The first successful rolling cutter rock bit was introduced into the oil field by Howard Hughes Sr. in 1909. Over the next fifteen years, the rolling cutter bit was used primarily in hard formation areas. This rolling cutter bit was a two-cone bit with cones that did not mesh, consequently, the bit had a tendency to balled-up in...
SlantedFace Rock Bits
Slanted-face rock bits are used in harder ground conditions and soft rock less than 3,500 psi that cannot easily be penetrated with thrust alone. The face of the tool usually has one or more nozzles emitting pressurized drilling fluid. In harder ground conditions, steering is accomplished by techniques such as partial rotation and release, wiggling the bit clockwise counterclockwise fishtailing while thrusting at the desired steering orientation, or by a broader arc of clockwise...
Desilter Suction and Discharge Pits Mud CleanerConditioner
The desilter suction pit is the desander discharge pit. The desilter will remove smaller particles than the desander, so its operation is downstream of the desander. Setup and operation of desilters are the same as with desanders. The manifold discharge is downstream of the suction, with a low equalizer between the two tanks. It is recommended that the desilter process more volume than the rig is pumping so that there is a backflow through the equalizer, ensuring that all of the drilling fluid...
Pills and Spacers
Both direct and indirect displacement procedures utilize pills and spacers for effective hole cleaning and separation of fluids. The primary purpose of a spacer is to provide complete separation of two incompatible fluids. The spacer must be compatible with both the displaced fluid and the displacing fluid. Cleaning pills are used to scour and sweep debris out of the hole. Two types of pills may be used. A basic cleaning pill is composed of viscosified drill water, seawater or brine. A scouring...
Simplified Roller Bit Classification System
A new roller bit classification system has been approved by the American Petroleum Institute as a recommended practice and It will be included in the forthcoming edition of RP7G. Recommended practice for drill stem design and operating limits . The system is meant to standardise the nomenclature for roller bits according to the application recommended by the manufacturer and their special features and not to standardise the bit design itself. A 3-digit code is used. The first digit series...
Advantages of NDS
Elimination of trips for directional assembly changes, saving rig time More complex well paths can be drilled Wells are drilled more closely to the plan at all times Smaller directional targets can be hit Steerable turbines use the side force method by having an eccentric or offset stabilizer at the lower end of the bearing section at the bottom end of the turbine body, quite close to the bit. The three blade version shown below is the one most commonly used, but a single blade version exists...