You must log in to edit PetroWiki. Help with editing

Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. More information


Drilling dynamics: Difference between revisions

PetroWiki
Jump to navigation Jump to search
No edit summary
No edit summary
 
Line 1: Line 1:
The aim of drilling-dynamics measurement is to make drilling the well more efficient and to minimize nonproductive time (NPT).
The aim of drilling-dynamics measurement is to make drilling the well more efficient and to minimize nonproductive time (NPT).


==Measured parameters==
== Measured parameters ==


Approximately 75% of all lost-time incidents of more than 6 hours are caused by drilling-mechanics failures.<ref name="r1" /> Therefore, extensive effort is made to ensure that the drilling-mechanics information acquired is converted to a format usable by the driller and that usable data are provided to the rig floor.  
Approximately 75% of all lost-time incidents of more than 6 hours are caused by drilling-mechanics failures.<ref name="r1">Burgess, T.M. and Martin, C.A. 1995. Wellsite Action on Drilling Mechanics Information Improves Economics. Presented at the SPE/IADC Drilling Conference, Amsterdam, The Netherlands, 28 February–2 March. SPE-29431-MS. http://dx.doi.org/10.2118/29431-MS.</ref> Therefore, extensive effort is made to ensure that the drilling-mechanics information acquired is converted to a format usable by the driller and that usable data are provided to the rig floor.


The most frequently measured downhole drilling-mechanics parameters are:
The most frequently measured downhole drilling-mechanics parameters are:


* Downhole mud pressures (pressure while drilling (PWD))
*Downhole mud pressures (pressure while drilling (PWD))
* WOB(Weight on bit)
*WOB(Weight on bit)
* Torque on bit
*Torque on bit
* Shock
*Shock
* Temperature
*Temperature
* Caliper
*Caliper


==Applications with formation testing while drilling (FTWD)==
== Applications with formation testing while drilling (FTWD) ==


[[Formation testing while drilling (FTWD)|Formation testing while drilling (FTWD)]] provides key formation pressures for drilling optimization. The data provided by these measurements are intended to enable informed, timely decisions by the drilling staff and thereby improve drilling efficiency. The two main causes of NPT are hole problems (addressed by hydraulics measurement and wellbore-integrity measurement) and drillstring and tool failure (addressed by drillstring-integrity measurement).
[[Formation_testing_while_drilling_(FTWD)|Formation testing while drilling (FTWD)]] provides key formation pressures for drilling optimization. The data provided by these measurements are intended to enable informed, timely decisions by the drilling staff and thereby improve drilling efficiency. The two main causes of NPT are hole problems (addressed by hydraulics measurement and wellbore-integrity measurement) and drillstring and tool failure (addressed by drillstring-integrity measurement).


==Data delivery to driller==
== Data delivery to driller ==


To have a positive effect on drilling efficiency, drilling dynamics must have a quick feedback loop to the driller. Recent advances have made it possible to observe the cyclic oscillations in WOB.<ref name="r2" />If the oscillations exceed a predetermined threshold, they can be diagnosed as bit bounce, and a warning is transmitted to the surface. The driller can take corrective action (such as altering WOB), and observe whether the bit has stopped bouncing on the next data transmission. Other conditions, such as “stick-slip” (intermittent sticking of the bit and drillstring with rig torque applied, followed by damaging release or slip) and torsional shocks, also can be diagnosed and corrected.
To have a positive effect on drilling efficiency, drilling dynamics must have a quick feedback loop to the driller. Recent advances have made it possible to observe the cyclic oscillations in WOB.<ref name="r2">Hutchinson, M., Dubinsky, V., and Henneuse, H. 1995. An MWD Downhole Assistant Driller. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, 22-25 October. SPE-30523-MS. http://dx.doi.org/10.2118/30523-MS.</ref>If the oscillations exceed a predetermined threshold, they can be diagnosed as bit bounce, and a warning is transmitted to the surface. The driller can take corrective action (such as altering WOB), and observe whether the bit has stopped bouncing on the next data transmission. Other conditions, such as “stick-slip” (intermittent sticking of the bit and drillstring with rig torque applied, followed by damaging release or slip) and torsional shocks, also can be diagnosed and corrected.


==Application of downhole shock sensors==
== Application of downhole shock sensors ==


Another application is the use of downhole shock sensors, which count the number of shocks that exceed a preset force threshold over a specific period. This number of occurrences is then transmitted to the surface. Downhole shock levels can be correlated with the design specification of the [[Measurement while drilling (MWD)|MWD]] tool. If the tool is operated above design thresholds for a period, the likelihood of tool failure increases proportionally. Of course, a strong correlation exists between continuous shocking of the BHA and the mechanical failure that causes the drillstring to part. In most cases, lateral-shock readings have been observed at significantly higher levels than axial (along the tool axis) shock.
Another application is the use of downhole shock sensors, which count the number of shocks that exceed a preset force threshold over a specific period. This number of occurrences is then transmitted to the surface. Downhole shock levels can be correlated with the design specification of the [[Measurement_while_drilling_(MWD)|MWD]] tool. If the tool is operated above design thresholds for a period, the likelihood of tool failure increases proportionally. Of course, a strong correlation exists between continuous shocking of the BHA and the mechanical failure that causes the drillstring to part. In most cases, lateral-shock readings have been observed at significantly higher levels than axial (along the tool axis) shock.


==Hydraulics management with PWD==
== Hydraulics management with PWD ==


Hydraulics management with PWD has proved a key enabling technology in extended-reach wells where long tangent sections may have been drilled. Studies performed on such wells have shown that hole cleaning can be difficult and that cuttings can build up on the lower side of the borehole. If this buildup is not identified early enough, loss of ROP(Rate of Penetration) and sticking problems can result. A downhole annulus-pressure measurement can monitor backpressure while circulating the mud volume, and, assuming that flow rates are unchanged, it can identify precisely if a wiper trip should be performed to clean the hole. '''Fig. 1''' shows an example in which cuttings have fallen out of suspension in the annulus during a period of sliding. Once rotation is resumed, the cuttings are agitated and suspended once more in the mudstream with a consequent increase in equivalent circulating density (ECD).  
Hydraulics management with PWD has proved a key enabling technology in extended-reach wells where long tangent sections may have been drilled. Studies performed on such wells have shown that hole cleaning can be difficult and that cuttings can build up on the lower side of the borehole. If this buildup is not identified early enough, loss of ROP(Rate of Penetration) and sticking problems can result. A downhole annulus-pressure measurement can monitor backpressure while circulating the mud volume, and, assuming that flow rates are unchanged, it can identify precisely if a wiper trip should be performed to clean the hole. '''Fig. 1''' shows an example in which cuttings have fallen out of suspension in the annulus during a period of sliding. Once rotation is resumed, the cuttings are agitated and suspended once more in the mudstream with a consequent increase in equivalent circulating density (ECD).


<gallery widths=300px heights=200px>
<gallery widths="300px" heights="200px">
File:Devol2 1102final Page 657 Image 0001.png|'''Fig. 1—Downhole sensors provide useful drilling measurements.'''
File:Devol2 1102final Page 657 Image 0001.png|'''Fig. 1—Downhole sensors provide useful drilling measurements.'''
</gallery>
</gallery>


In wells in which there is a narrow window between pore pressure and fracture gradient (e.g., deep water), the uncertainties can be reduced greatly through the use of PWD and [[Formation testing while drilling (FTWD)|FTWD]] technology. Downhole measurement and transmission of leakoff tests eliminate errors associated with surface measurements. Real-time Equivalent Circulating Density (ECD) measurements pinpoint key pressure parameters frequently and accurately. Finally, real-time measurement of pore pressure identifies exactly the mud weight required.
In wells in which there is a narrow window between pore pressure and fracture gradient (e.g., deep water), the uncertainties can be reduced greatly through the use of PWD and [[Formation_testing_while_drilling_(FTWD)|FTWD]] technology. Downhole measurement and transmission of leakoff tests eliminate errors associated with surface measurements. Real-time Equivalent Circulating Density (ECD) measurements pinpoint key pressure parameters frequently and accurately. Finally, real-time measurement of pore pressure identifies exactly the mud weight required.


==References==
== References ==


<references>
<references />
<ref name="r1">Burgess, T.M. and Martin, C.A. 1995. Wellsite Action on Drilling Mechanics Information Improves Economics. Presented at the SPE/IADC Drilling Conference, Amsterdam, The Netherlands, 28 February–2 March. SPE-29431-MS. http://dx.doi.org/10.2118/29431-MS.</ref>
<ref name="r2"> Hutchinson, M., Dubinsky, V., and  Henneuse, H. 1995. An MWD Downhole Assistant Driller. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, 22-25 October. SPE-30523-MS. http://dx.doi.org/10.2118/30523-MS.</ref>
</references>


==See also==
== See also ==
[[PEH:Drilling-Data Acquisition]]


==Noteworthy papers in OnePetro==
[[PEH:Drilling-Data_Acquisition]]


Dubinsky, V.S. and Baecker, D.R. 1998. An Interactive Drilling Dynamics Simulator for Drilling Optimization and Training, SPE Annual Technical Conference and Exhibition, 27-30 September. 49205-MS. http://dx.doi.org/10.2118/49205-MS.
== Noteworthy papers in OnePetro ==


Heisig, G., Sancho, J. and Macpherson, J.D. 1998. Downhole Diagnosis of Drilling Dynamics Data Provides New Level Drilling Process Control to Driller, SPE Annual Technical Conference and Exhibition, 27-30 September. 49206-MS. http://dx.doi.org/10.2118/49206-MS.
Dubinsky, V.S. and Baecker, D.R. 1998. An Interactive Drilling Dynamics Simulator for Drilling Optimization and Training, SPE Annual Technical Conference and Exhibition, 27-30 September. 49205-MS. [http://dx.doi.org/10.2118/49205-MS http://dx.doi.org/10.2118/49205-MS].


==External links==
Heisig, G., Sancho, J. and Macpherson, J.D. 1998. Downhole Diagnosis of Drilling Dynamics Data Provides New Level Drilling Process Control to Driller, SPE Annual Technical Conference and Exhibition, 27-30 September. 49206-MS. [http://dx.doi.org/10.2118/49206-MS http://dx.doi.org/10.2118/49206-MS].
[[Category: 1.6 Drilling Operations]]
 
== External links ==
 
==Category==
[[Category:1.6 Drilling operations]] [[Category:YR]]

Latest revision as of 13:43, 26 June 2015

The aim of drilling-dynamics measurement is to make drilling the well more efficient and to minimize nonproductive time (NPT).

Measured parameters

Approximately 75% of all lost-time incidents of more than 6 hours are caused by drilling-mechanics failures.[1] Therefore, extensive effort is made to ensure that the drilling-mechanics information acquired is converted to a format usable by the driller and that usable data are provided to the rig floor.

The most frequently measured downhole drilling-mechanics parameters are:

  • Downhole mud pressures (pressure while drilling (PWD))
  • WOB(Weight on bit)
  • Torque on bit
  • Shock
  • Temperature
  • Caliper

Applications with formation testing while drilling (FTWD)

Formation testing while drilling (FTWD) provides key formation pressures for drilling optimization. The data provided by these measurements are intended to enable informed, timely decisions by the drilling staff and thereby improve drilling efficiency. The two main causes of NPT are hole problems (addressed by hydraulics measurement and wellbore-integrity measurement) and drillstring and tool failure (addressed by drillstring-integrity measurement).

Data delivery to driller

To have a positive effect on drilling efficiency, drilling dynamics must have a quick feedback loop to the driller. Recent advances have made it possible to observe the cyclic oscillations in WOB.[2]If the oscillations exceed a predetermined threshold, they can be diagnosed as bit bounce, and a warning is transmitted to the surface. The driller can take corrective action (such as altering WOB), and observe whether the bit has stopped bouncing on the next data transmission. Other conditions, such as “stick-slip” (intermittent sticking of the bit and drillstring with rig torque applied, followed by damaging release or slip) and torsional shocks, also can be diagnosed and corrected.

Application of downhole shock sensors

Another application is the use of downhole shock sensors, which count the number of shocks that exceed a preset force threshold over a specific period. This number of occurrences is then transmitted to the surface. Downhole shock levels can be correlated with the design specification of the MWD tool. If the tool is operated above design thresholds for a period, the likelihood of tool failure increases proportionally. Of course, a strong correlation exists between continuous shocking of the BHA and the mechanical failure that causes the drillstring to part. In most cases, lateral-shock readings have been observed at significantly higher levels than axial (along the tool axis) shock.

Hydraulics management with PWD

Hydraulics management with PWD has proved a key enabling technology in extended-reach wells where long tangent sections may have been drilled. Studies performed on such wells have shown that hole cleaning can be difficult and that cuttings can build up on the lower side of the borehole. If this buildup is not identified early enough, loss of ROP(Rate of Penetration) and sticking problems can result. A downhole annulus-pressure measurement can monitor backpressure while circulating the mud volume, and, assuming that flow rates are unchanged, it can identify precisely if a wiper trip should be performed to clean the hole. Fig. 1 shows an example in which cuttings have fallen out of suspension in the annulus during a period of sliding. Once rotation is resumed, the cuttings are agitated and suspended once more in the mudstream with a consequent increase in equivalent circulating density (ECD).

In wells in which there is a narrow window between pore pressure and fracture gradient (e.g., deep water), the uncertainties can be reduced greatly through the use of PWD and FTWD technology. Downhole measurement and transmission of leakoff tests eliminate errors associated with surface measurements. Real-time Equivalent Circulating Density (ECD) measurements pinpoint key pressure parameters frequently and accurately. Finally, real-time measurement of pore pressure identifies exactly the mud weight required.

References

  1. Burgess, T.M. and Martin, C.A. 1995. Wellsite Action on Drilling Mechanics Information Improves Economics. Presented at the SPE/IADC Drilling Conference, Amsterdam, The Netherlands, 28 February–2 March. SPE-29431-MS. http://dx.doi.org/10.2118/29431-MS.
  2. Hutchinson, M., Dubinsky, V., and Henneuse, H. 1995. An MWD Downhole Assistant Driller. Presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, 22-25 October. SPE-30523-MS. http://dx.doi.org/10.2118/30523-MS.

See also

PEH:Drilling-Data_Acquisition

Noteworthy papers in OnePetro

Dubinsky, V.S. and Baecker, D.R. 1998. An Interactive Drilling Dynamics Simulator for Drilling Optimization and Training, SPE Annual Technical Conference and Exhibition, 27-30 September. 49205-MS. http://dx.doi.org/10.2118/49205-MS.

Heisig, G., Sancho, J. and Macpherson, J.D. 1998. Downhole Diagnosis of Drilling Dynamics Data Provides New Level Drilling Process Control to Driller, SPE Annual Technical Conference and Exhibition, 27-30 September. 49206-MS. http://dx.doi.org/10.2118/49206-MS.

External links

Category