directional drilling - · pdf file• early drilling for oil and gas was almost always...
TRANSCRIPT
![Page 1: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/1.jpg)
Directional Drilling
• - Acknowledgement• - History• - Present Day Applications• - Hardware• - Measurement Sensors• - Error sources and Equipment Limitations• - Mathematics• - Legislation
![Page 2: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/2.jpg)
Acknowledgement
This presentation has been inspired by many of the items discussed in the publication at left.It can be downloaded at: http://www.uhi.ac.uk/en/research-enterprise/energy/wellbore-positioning-download
Additional material has been obtained from publications of;APSG, OGP, EPSG, C-NLOPB and others
![Page 3: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/3.jpg)
History
Rotary drilling techniques were developed in early 20th century.
Deviated wellbores were usually drilled unintentionally.
![Page 4: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/4.jpg)
• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3° of plumb.
• Wellbores could naturally deviate from the vertical when certain forces were applied and/or geological conditions existed.
• Until the 1970’s downhole surveys were primarily used to monitor lateral deviations of a wellbore and take preventive measures to maintain its verticality should it start to drift off to one side.
• Deliberately causing a wellbore to deviate from the vertical was known as whipstocking and considered illegal.
![Page 5: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/5.jpg)
• In 1930, California driller John Eastman was granted a patent for his techniques of conducting downhole surveys and intentionally deviating a wellbore.
• Founded the Eastman Oil Well Survey Company.
• He achieved fame and credibility in 1934 by drilling a directional relief well to intercept and extinguish another that was burning near Conroe, Texas.
• Similar research by Sperry, a gyrocompass manufacturer, and Sun Oil Company lead to Sperry-Sun Drilling Services.
• Both Eastman and Sperry names live on as directional drilling subdivisions of major Oil industry service companies.
• In 1964 there was a test in Utah running competing survey tools inside an aluminium irrigation pipe installed on a mountain side. This proved the validity of such equipment and several lawsuits were settled as a result.
![Page 6: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/6.jpg)
![Page 7: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/7.jpg)
![Page 8: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/8.jpg)
![Page 9: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/9.jpg)
Present Day Applications
![Page 10: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/10.jpg)
• Large numbers of present day production and development wells are deviated.
• Environmental and economic benefits.
• Allows for enhanced recovery techniques
![Page 11: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/11.jpg)
• Reuse old wellbores
• Drill a relief well as required by regulations
• Sidetrack around broken pipe and ‘fish’
![Page 12: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/12.jpg)
![Page 13: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/13.jpg)
Hardware
![Page 14: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/14.jpg)
![Page 15: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/15.jpg)
![Page 16: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/16.jpg)
![Page 17: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/17.jpg)
![Page 18: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/18.jpg)
![Page 19: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/19.jpg)
![Page 20: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/20.jpg)
Measurement Sensors
![Page 21: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/21.jpg)
Retrievable Magnetic Compass Survey Equipment
![Page 22: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/22.jpg)
Equipment Limitationsand Error Sources
• Measurements are limited to:GyroscopesMagnetometersAccelerometers
• All components have to be small to fit inside wellbore
• Magnetometers cannot be used inside cased hole
• From a surveyor’s point of view, directional surveys are unclosed traverses and thus will always be suspect.
• Despite this, most errors are in the blunder category
![Page 23: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/23.jpg)
Gamma ray sensor installed behind bit to identify rock formations
MWD probe tracks nearby induced magnetic field
Alternative methods of wellbore steering.
![Page 24: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/24.jpg)
Mud Pulsing Data Transmission
![Page 25: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/25.jpg)
Electromagnetic Data Transmission
$$$$$$$$$$$$$$$
![Page 26: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/26.jpg)
![Page 27: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/27.jpg)
Getting the data back can be problematic.
• Mud Pulse TelemetryLow data rate Cannot be used in underbalanced drilling programs
• Electromagnetic TelemetryDepth limitationsNeed to isolate components
• Retrievable ToolsLow data rateTime consuming Small diameter components
• Wired ToolsConnectivity problemsWire damage potential
• Wired Drill PipeHigh capital costA work in progress
![Page 28: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/28.jpg)
Mathematics
![Page 29: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/29.jpg)
Example - Wellbore Survey Calculations
The table below gives data from a directional survey.
Survey Point Measured Depth Inclination Azimuthalong the wellbore Angle Angle
ft I, deg A, deg
A 3,000 0 20B 3,200 6 6C 3,600 14 20D 4,000 24 80
Based on known coordinates for point C we’ll calculate the coordinates of point D using the above information.
![Page 30: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/30.jpg)
Point C has coordinates:
x = 1,000 (ft) positive towards the east
y = 1,000 (ft) positive towards the north
z = 3,500 (ft) TVD, positive downwards
Z
E (x)
N (y)C
D
DzN
D
C
Dy
Dx
![Page 31: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/31.jpg)
I. Calculate the x, y, and z coordinatesof points D using:
(i) The Average Angle method
(ii) The Balanced Tangential method
(iii) The Minimum Curvature method
(iv) The Radius of Curvature method
(v) The Tangential method
![Page 32: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/32.jpg)
Summary of Results (to the nearest ft)
X Y Z
Average Angle 1,100 1,084 3,878
Balanced Tangential 1,097 1,060 3,877
Minimum Curvature 1,098 1,060 3,881
Radius of Curvature 1,095 1,080 3,878
Tangential Method 1,160 1,028 3,865
![Page 33: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/33.jpg)
Even the most elaborate of these five calculations can be written onto an MS Excel spreadsheet
![Page 34: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/34.jpg)
![Page 35: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/35.jpg)
Do try to maintain standards for data exchange as described in: http://www.epsg.org/exchange/p7.pdf
![Page 36: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/36.jpg)
Legislation
• Surface LocationCanada Oil and Gas Drilling and Production Regulations - Section 74Oil and Gas Conservation Regulations (Alberta) – Section 2.020Both require a licenced surveyor to certify plan
• Directional SurveysCanada Oil and Gas Drilling and Production Regulations - Section 32The operator shall ensure that:(a) directional and deviation surveys are taken at intervals that allow the position of the well-bore to be determined accurately; and(b) except in the case of a relief well, a well is drilled in a manner that does not intersect an existing well.
![Page 37: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/37.jpg)
Oil and Gas Conservation Regulations (Alberta) – Section 6.030(1) Unless the Board otherwise directs in writing, the licensee of a well shall make or cause to be made during drilling, tests, at depth intervals not exceeding 150 metres, for the purpose of ascertaining to what extent the well deviates from the vertical. (2) Repealed AR 36/2002 s6.(3) The licensee shall, immediately upon the making of a directional survey, send to the Board the report of the survey (4) The Board may order the licensee to make such further deviation or directional surveys as it deems necessary, and may give directions as to the manner in which such tests or surveys shall be made.
• SummaryNeither jurisdiction requires directional survey data to be tied to surface location.No certification requirement for directional survey.
![Page 38: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/38.jpg)
Nevertheless; directional surveys may be related to legal boundaries!
![Page 39: Directional Drilling - · PDF file• Early drilling for oil and gas was almost always performed by drilling vertical wells, usually considered to be within 2°-3°of plumb. • Wellbores](https://reader033.vdocuments.us/reader033/viewer/2022051717/5a7028c77f8b9aac538bad88/html5/thumbnails/39.jpg)
Legal Cases
• East Texas Scandal 1962Several land owners believed that deviated wells had been drilled beneath their properties from adjacent lands.Surveys were ordered and over 380 wells were found to be deviated across land boundaries.The validity of surveying equipment used was upheld after the Utah tests in 1964.
• Bocardo SA v Star Energy UK Onshore et al 2009Land owner, Mr. Al Fayed, alleged that 17 years earlier Star had drilled a deviated well underneath his property to extract oil and gas.Star denied the ‘theft’ in initial negotiations but admitted it in court several years later.Judgement for trespass in Bocardo’s favour ; awarded 9% of income over a limited period of time.