Vibration Analysis is a new procedure to many people, not only Datalog engineers, but to many drilling and company personnel.
A procedural form has been created to help the Datalog engineer understand the vibrational software and use it effectively. By using the material available in this manual and by following the procedures and guidelines, you can have confidence in the analysis you are performing and that you are using the software correctly and to full advantage.
Just as importantly, you will be able to impart this confidence to the drilling representatives. It is crucial that they understand what vibrational analysis is all about: -
• How torsional vibration occurs
• The potential problems, and costs, created when it occurs • How it can be recognised
• How our particular system operates and how everyone can utilize it to maximize cost savings for the operation.
1. OBJECTIVE
This document is designed as a guideline or checklist to establish the general procedures for installation and operation of the Datalog Stick Slip program. It does not replace the manual.
2. DEFINITIONS AND ABBREVIATIONS
!"STICK SLIP is Datalog´s real time vibration monitoring program. If set up
and used correctly, it can quickly detect and identify undesirable vibrational occurrences that adversely affect the drillstring. This is achieved through high frequency analysis of torque cycles together with user interpretation of RPM, pump pressure and hookload fluctuations. This program is eventually to be implemented in each mudlogging unit, where it is recommended to have a separate node and screen specifically for running this program.
!"TRAFFIC LIGHT: This is located on the rig floor and is a warning system
for the driller, indicating the degree of stick slip present at any given moment. It consists of green, amber and red lights, sequentially activated by the duration of the stick slip condition.
3. UTILIZATION
Datalog intends on installing and implementing this service in each unit and impressing on operators its potential importance in helping to avoid wasted operational time and reduce operational and equipment costs. However, the programme is very dependant on the skills of the Datalog operator in identifying and classifying vibrational phenomena.
4. SUPPORT DOCUMENTS
!"In the Datalog office and in each unit, there will be up to date Stick Slip manuals and additional information such as technical papers and references.
5. PRODUCTS
RPM, pump pressure and hookload are recorded at high frequency and graphically displayed on screen while the programme is running. The torque signal, as well as being displayed with the other parameters, is analysed by the programme, using the Datalog Stick Slip algorithm. Cycle frequency and amplitude are considered within the analysis. Torque, SPP and hookload are all sampled at 10 times per second and RPM once per second. Data is stored in a daily database format. Any information can be displayed with hard copy graphical or ASCII data dump format.
6. PROCEDURAL GUIDE
WHO ACTIVITY
1 Data Engineer Logging Geologist
Check verbally with the technical department that the latest version has been installed or is present from stkslp.zoo. Configure the dedicated Stick Slip node for running the QNX-windows based program.
2 Data Engineer Logging Geologist
If the latest version has not been installed, use the following procedure:
3 Logging Geologist Data Engineer
1. Copy the latest version of stkslp.zoo into the temporary directory, 3:/tmp. It is a small file, which can comfortably be sent via email or hand carried on a floppy.
2. List the contents of the stkslp.zoo file. (zoo l stkslp.zoo) Any files present in the system already with the same name, i.e. older versions, will be overwritten by the new version at the operators command.
3. Once this is done, extract the contents of the stkslp.zoo file (zoo xS stkslp.zoo).
4. Shut down the administrators with dau_kill +a, and restart. Run the Stick Slip administrators from the dedicated node after starting QNX Windows. Open a shell and start them from there.
5. To run the program, we need the following administrators
$ stkslpacq & $ stkslpanl & $ stkslpdbase & $ stkslpwin &
Always start stkslpwin last, as this command opens the window to the programme. If the other administrators are not running, the programme will not run.
6. A window should open titled “Stick Slip”. This window, when left-clicked, will display:
Time Chart Setup
-Display length: Time interval in which torque, RPM, SPP and hookload are displayed. A two minute resolution is recommended to start with.
Data Chart Setup
-Parameter scales: The most narrow scale practical, whilst rotary drilling, is necessary for each of the four displayed parameters. For example, if we have an average torque reading of 15,000 ftlb, our range on the scale should be 10,000 to 20,000 ftlb rather than 0 to 30,000 ftlb. This allows a much easier interpretation of data, and is far more presentable graphically.
Stkslp Trend Setup
-SS factor alarm level: The user defined value used to indicate the presence of stick slip. It is based on the alarm timeout function, which is the amount of time that a stick slip condition is said to
exist. If the user has decided that a stick slip condition must exist for 60 seconds before the stick slip trend graph reaches 100%, then after 30 consecutive seconds of a stick slip condition, the graph will show a stick slip trend of 50%. The system alarm and rig floor traffic light are based on the SS factor, with user defined points for the amber and red levels of stick slip. The traffic light is not an indicator of severity, it is an indicator of duration – in order for it to pass from green to yellow or red, the predetermined levels of amplitude and frequency will already have been met.
Report Control Setup
-Start/End Time: Any given time period can be displayed in graphical format, presented as an historical HPGL plots. After setting the time desired, the written file will be displayed in
3:/datalog/stkslp/yymmdd_hhmm.n. These files can then be
converted into PCX or PDF format for presentation.
-Minutes per page: The time interval desired for each page. If a graphic is requested between the interval 10:00 to 10:30 and 10 minutes per page is selected, three files will be created:
3:/datalog/stkslp/20000205_1000.1...From 10:00 to 10:10 3:/datalog/stkslp/20000205_1000.2...From 10:10 to 10:20 3:/datalog/stkslp/20000205_1000.3...From 10:20 to 10:30
-ASCII dump: This is numeric information in ASCII code, corresponding to the selected time period, e.g. from 10:00 to 10:30. It is written to, and found in:
3:/datalog/stkslp/yymmdd_hhmm.d
For the date 27 March 2001 starting at 10am, the file would appear as 3:/datalog/stkslp/010327_1000.d
Stkslp Analysis Setup
The correct setting of these parameters is vital if a stick slip condition is going to be identified.
-Alarm timeout: The duration that a stick slip condition must exist before the unit alarm will sound.
-High Hz: The upper limit of torque frequency in Hertz (cycles pre second), normally set at 1.5 to 2.0 hz. The frequency of the torque signal oscillations must be lower than this number. If they are not, change it.
-Low Hz: The lower limit of torque frequency in Hertz, set anywhere from 0.2 to 1.0 Hz. Torque must be cycling at a higher rate than this to indicate a stick slip condition.
-Minimum amplitude setpoint: The lower limit for the amplitude of the torque oscillations, measured peak to trough of one cycle. The amplitude must be higher than this value to indicate a stick slip condition. Setting this value is dependant on the local conditions. -Amber and Red alarm levels: These are the values for the traffic light indicators. A recommended level to use is 30% for the amber alarm and 80% for the red. If the stick slip trend has been set at 60 seconds for a 100% stick slip condition, this would warn the driller with an amber light if a stick slip condition exists for around 20
secs, and a red light if the condition has been present for 50 secs. The setting of these parameters is entirely dependant on local conditions.
7. The information recorded daily is stored in:
3:/datalog/stkslp/data/dd_mm_yyyy.dat
This is a very big file (17000+ blocks) and must be zoo´ed or zipped and saved on another computer (either another node or sent to the DOS computer via Hyperlink). It is recommended to do this daily to avoid filling the hard disk on node 1.
4 Logging Geologist Data Engineer
When a cyclic torque condition is first observed, our primary responsibility is to inform the driller and company man. We must then try to analyse and understand the situation and endeavour to help find the solution.
After the resolution of the situation, check with the operator as to what kind of data presentation is required. It is suggested that with a graphical plot, the 10 minutes before and after the event are also displayed for comparison.
7. CHECK RECORD
No. Check
Check Date Authority Author Check Details
1 February 2001 Rubén
Mejía
Creation of first format
2 March 2001 Lewis
Evans
Update and conversion to English.
Appendix A – Traffic Light Wiring
The current limiting resistor value is determined by the supply voltage and the LED Bias Current, typically 20mA.
Therefore, connected to a 12V supply rail, the resistor value will be:
12 / 20mA = 600 Ohms
R1, R2 and R3 are pull-up resistors, with typical values 4K7 or 10Kohm. The purpose of the pull-up resistor is to prevent fault conditions.