8.0 – Engineering Parameters Tab
8.1 – Hydraulics module parameters
This section allows the parameters for the hydraulics module to be specified.
Hydraulics Model – four models are included as standard
Bingham Plastic
Power Law
Herschel Bulkley
Robertson Stiff
Bingham plastic uses PV and YP and mud weight, all other models use the fann readings and mud weight.
Surge / Swab – Specifies if the surge and swab calculation to be carried out is Open or Close Ended. If modelling for a casing or liner assembly and close ended is used, the pressure loss through the float / shoe is taken into account
Surge / Swab Reference – This is the reference point for the surge / swab calculation. Select common references from the combo box:
Bit – Bit depth
Shoe –Shoe depth, taken from the well geometry dialogue in the drill string tab
Bottom Hole – Bottom hole depth, taken from the well geometry dialogue in the drill string tab
Or click on the check box to enable a User Defined Depth.
User defined depth – Only active if the enable check box has been ticked. This will disable the surge / swab reference combo above and the surge and swab reference depth can be entered in the edit box.
ROP – Rate of penetration. This is used to calculate the cuttings loaded (Dirty) ECD’s and other hole cleaning parameters
RPM – The rotational speed of the drill string. Additional pressure will be added based on the RPM
ECD Adj – ECD adjustment is manual adjustment to all the ECD curves to better match the model with MWD PWD data.
SW Den – Sea water density, which is used for riserless drilling calculations. Default is 8.55ppg.
Surface Pressure Losses – The pressure loss through the surface equipment. This value is added to the total standpipe pressure calculated by the model.
Calc Depth – This is the depth at which the calculation will be run and the depth at which snap shot calculations will be performed. This depth must be within the range of the surveys for a directional well.
8.2 – Flow Rates
This grid allows the flow rates for the hydraulics model to be entered. By default, the manual flow increment box is unchecked, and the user enters a flow rate in the middle cell of the grid. The software then automatically calculates flow rates above and below this base rate (±25% & 50%) with which to perform a sensitivity analysis. If you wish to override the automatic values generated, click the enable manual flow increment check box. This will leave the user with a single line and once filled a new line will be added. An unlimited number of flowrates can be entered.
For torque and drag calculations, if a flow rate has been entered, Engineering will use this in the calculations. If manual flow increment is selected, the first flow rate entered will be used in the T&D calculations. If the automatic range is selected, the flow rate entered in line 3 will be used.
8.3 - Tripping speeds
This grid allows the tripping speeds for the hydraulics model to be entered. By default, the manual tripping increment box is unchecked, and the user enters a tripping speed in the middle cell of the grid. The software then automatically calculates tripping speeds above and below this base rate (±25% & 50%) with which to perform a sensitivity analysis. If you wish to override the automatic values generated, click the enable manual trip increment check box. This will leave the user with a single line and once filled a new line will be added. An unlimited number of trip speeds can be entered but the first trip speed entered will be used for the reports.
8.4 – Survey Selection
The survey selection box is used for both the hydraulics and torque and drag module. It allows the user to select which survey listing is to be used for the calculation.
Actual surveys – Use actual survey grid
Well Plan – Use well plan grid
Composite – Splice the actual surveys into the well plan surveys to create a composite listing. The surveys will be used from surface, and the plan will tie-onto the last survey station.
8.5 – Torque and Drag parameters
This section allows the parameters of the torque and drag model to be defined:
Calc Depth – This is the depth at which the calculation will be run and also the depth the snapshot graphs and tables will display
RPM – Rotational speed of the drill string, used to calculated reaming torques and hook loads
Pipe speed – The speed the pipe is moving up and down in depth units / min. Used to calculate reaming hook loads and torques. It is also used to calculate the viscous drag if selected
WOB – The weight on bit while Rotary drilling
WOB Slide– The weight on bit while Slide drilling. If the check box is not selected, this will auto populate with the value in the WOB cell.
Overpull - The overpull applied to the assembly when pulling out of hole. Used for creating the Apparent Overpull & Apparent Overpull Snapshot Charts
Block weight – The weight of the travelling block
Block PU – If the weight of the travelling block is different to the block weight while picking up, enter it here. Click the check box to enable
Block SO - If the weight of the travelling block is different to the block weight while slacking off, enter it here. Click the check box to enable
Optimise Standoff – Used in the casing standoff calculation. This will override the centralizer spacing selected in casing component details, and output the spacing required to achieve the desired standoff.
Bit Torque – The estimated torque generated by the bit. This is calculated from the WOB and the bit OD (taken from the drill string), however it can be over-ridden with a user defined value by clicking the check box.
Side force units – Specifies the unit length of the calculated side force. It should be noted that if you are using side force to predict casing wear, the default units should be over ridden to side force / per tool joint (ie. 30ft or 10m).
Casing Wear Factor – Casing wear factor, defined as the ratio of friction factor to specific energy, E-10psi-1. The table below should be used as guide for casing wear factor selection. Default is 1.
ROP – The rate of penetration in feet or meters / hour. The ROP is used to calculate the casing wear. This is done by taking the depth of the last casing or liner and subtracting it from the calculation depth. This value is then divided by the ROP to give the time over which casing wear is calculated.
Friction factor grid – The friction factors for cased hole and open hole. By default, the enable manual increment box is disabled. If this is the case, enter a friction factor for the cased hole and open hole in the middle cells of each column and values above and below will automatically be calculated (±25% &±50%) in order to perform a sensitivity analysis. If you wish to override this feature, click the check box and enter as many friction factors as required. This can also be used to perform a single friction factor calculation.
8.6 – Hydraulics Results
This section displays the results from the hydraulics module once the hydraulics have been calculated. The grid in the top left displays the pressure loss for the bit and any other pressure losses from specific tools in the drill string such as MWD and motors. The grid at the top right displays a summary of the stand pipe pressures, annular pressure loss and ECD’s for all the flow rates selected.
The bottom grid gives an overview of the pressure losses and flow regime in each pipe section and each hole section. The results for different flow rates can be viewed by selecting them from the “Flow” combo box at the top of the section. The overview grid results can be viewed for different depths by clicking on the spin button to the right of the flow combo box.
8.7 – Torque and Drag Results
A summary of the torque and drag results are displayed in the grids once the torque and drag has been calculated. Only hook loads and torques are displayed. Full results can be obtained by viewing the data tables from the TAD results menu.
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