BHA and Bit Data

Interactive Well Site > Available Daily Operations Data

The BHA Runs form is used to build the components that make up the BHA, including the drillstring and bit. In addition, this form also records operation performance information.

Typically, a BHA Run is an event that begins when a drillstring is run down the hole and ends when the drillstring is changed or pulled out of the hole.

Note: Deleting a BHA Run will delete the run, assembly string, associated components, and all operations (Bit and BHA).

BHA and Bit data is recorded from the surface and subsurface Daily Operations link or by selecting the Drillstring/Bit image on the subsurface canvas.

The BHA and Bits form allows the user to add, review, modify and delete BHA and Bit data on a daily basis.

WARNING! Before a new BHA or Work String can be added, any previous BHA's or Work Strings MUST be pulled. This means their Date/Time Out and MD Out  fields must be entered. If these values are not entered, the following message will appear, "The previous drillstring/work string has to be pulled out before you can add a new one."

This form includes two spreadsheets.

• The BHA Runs spreadsheet is used to:

• run and pull the BHA

• define the components that make up the BHA (including the Bit)

• For easy viewing of bits, the Bit component entered with each BHA Run is also displayed in a separate spreadsheet. Each Bit in the Bits spreadsheet is connected to a BHA Run in the BHA Runs spreadsheet.
  
  The Bits spreadsheet can be used to:

• record Bit operation data

• record a Bit prior to defining the BHA Run

Wellbore Schematic Note: Use the wellbore schematic, built into the BHA Runs form, to verify the data being entered makes sense. Right-click the schematic to magnify the image.  

BHA and Bit Data can be entered using a number different workflows. The following topics outline two of these workflows.

• Record a BHA Run including the Bit and Bit Operation - In this workflow the user enters the details of the BHA Run including the Bit and enters Bit operation data in the Bits spreadsheet. This workflow includes running and pulling the BHA.

• Record a Bit prior to entering the details of the BHA Run - In this workflow the user enters the Bit and Bit operation directly into the Bits spreadsheet without defining the BHA. This workflow includes running and pulling the BHA.

Special Fields and Functions

Some fields on this form are automatically populated from data entered in areas of the application, involve calculations performed by OpenWells® software or have other significant features.

Copy To Library Button

This button allows drillstrings to be added to a library, where they can be used later to create new BHA Runs.

Select the row to be copied and click the Copy To Library button.

The Save String to Library dialog appears.  

Enter a String Name that clearly identifies the selected BHA string and click OK.

The string is now available to be copied from the Library.

Copy from Library

Prior to using this button, all drillstrings must be pulled.

The Copy from Library button copies a drillstring selected from the library to the current BHA Run Summary spreadsheet. When this button is selected the Select String from Library dialog appears.

Select the desired drillstring and click OK.

 A new BHA Run Summary row is added to the spreadsheet containing following data from the original BHA:

• the BHA No is a combination of the word "Copy and the name of the original BHA No,

• the String Type (defined by the name of the Library item,

• the current report date and the report date end time,

• components of the original BHA.

Edit these fields to correctly reflect the name of the BHA going into the Well and the date and time the BHA run took place.

Note: The Component Lengths most likely need to be altered when a drillstring is copied from the library.

Copy Previous Button

Prior to using this button, all drillstrings must be pulled.

The Copy Previous button copies a previously entered drillstring or planned drillstring into the BHA Run spreadsheet.

When this button is selected the Select Assembly String dialog appears.

Use the Select Existing String to Copy tab to access a BHAs recorded in EDM or use the Select Planned String to Copy tab to access a planned or prototype BHA recorded in EDM.

Navigate to the Wellbore containing the drillstring to be copied using the Well Explorer tree or click the Well List tab at the bottom of the dialog to select by well name and wellbore name.

Select the Wellbore. A list of BHAs recorded for the selected Wellbore appears.

Select the BHA to be copied and click OK.

The selected BHA is copied into the BHA Runs spreadsheet.

Edit the BHA No and Date/Time In fields to accurately reflect the new BHA Run.

MD In and Date/Time In

The MD In and Date/Time In fields define the depth and time at which the string is run "downhole".

The Date/Time In field automatically populates based on the date of the Daily Report date and the Reporting Standard selected for the Company (see Company Properties). For all subsequent rows, the Date/Time In field will be automatically populated with the data entered in the Date/Time Out field in the previous row.

MD Out and Date/Time Out

The MD Out and Date/Time Out define the work string as pulled.

Note: Before a new row can be added any Work String or Drillstring spreadsheets, the Date/Time Out and MD Out  fields for the previous row must be entered. If these are not entered, the following message will appear, "The previous BHA/Work String has to be pulled out before you can add a new one."

Catalog Button

The Catalog button is used to select a component from a compiled list of available components and their properties. For more information, see the Catalogs topic.

Flip BHA Button

In the event that a string's components have been entered in the wrong order (e.g., top to bottom instead of bottom to top), the Flip BHA button allows a user to quickly fix this mistake and reverses the entry order of the components.  

Move Up and Move Down Buttons

The move up and down buttons allow users to change the order of individual components. To change the order, select the component row and click the Move Up or Move Down button until the component is in the correct position in the spreadsheet.

Components  (Enter Top to Bottom) Label

The direction in which components must be added to the Components spreadsheet is defined in the Components (Enter Top to Bottom) text.  The direction displayed is defined in the Form's WYSIWYG XML file.

Running and Pulling a BHA in the OpenWells® application

In the OpenWells application:

• a BHA is considered downhole when both the MD In and Date/Time In have been entered

• a BHA is considered "pulled" when both the MD Base and Date/Time Out have been entered

• only one BHA or Work String can be run  "downhole" at a time

BHA Number

The BHA No. field is used to identify the BHA Run. For example, the BHA number can increment by one every time any component is changed. Individual Companies have their own rules for the BHA number.

MD In

The MD In defines the beginning depth at which the string begins the intended function.

Date/Time In

The Date/Time In defines the date and time the drillstring begins to enter the Well. When a new BHA is added, OpenWells automatically sets the Date/Time In field to one second after the previous BHA was pulled.

MD Out

The MD Out defines ending depth at which the string ends its intended function.

The drillstring is defined as "pulled" when the Date/Time and MD Out fields are completed.

Date/Time Out

The Date/Time Out defines the date and time the drillstring is removed from the Well or component change out is complete.

The drillstring is defined as "pulled" when the Date/Time and MD Out fields are completed.

BHA Length

The BHA Length is calculated as follows:

BHA Length =  ∑ all Component Lengths - the Drill Pipe Component Length at the top of the string

Note:  If the first spreadsheet row (i.e., the top of the string) is "Drill Pipe" then it is not included in the calculation.

Drag

The Drag field is calculated as follows:

Drag = String Wt Up - String Wt Rot

Footage

Footage is the amount of hole drilled since the BHA operation. This field is calculated as follows:

Footage = MD (of current BHA operation) - MD (of previous BHA operation)

ROP

The ROP field is calculated as follows:

ROP = Footage / Drilling Hours

Cum Drilling

The Cumulative Drilling (hours) field is calculated as follows:

Cum Drilling = ∑ Drilling Hours for all BHA Operations for the current Drillstring

Cum Circulating

The Cumulative Circulating (hours) field is calculated as follows:

Cum Circulating = ∑ Circulating Hours for all BHA Operations for the current Drillstring

Cum String

The Cumulative String (hours) field is calculated as follows:

Cum String = Cum Drilling + Cum Circulating

MD Top

The MD Top defines the top measured depth of the component. This field is calculated as follows:

For the first row, the value in the Top field is 0.0 based on the Depth Reference selected at the time the row was created. If the Depth Reference is changed the Top depth changes to reflect the new Depth Reference selected.

For all subsequent rows: Top = Previous MD Base

 MD Base

The MD Base field defines the bottom measured depth of the component. This field is calculated as follows:

MD Base = Top + Length

Section Type and Component Type Picklists

For each component, select the Section Type and Component Type from the picklists.

Some component Section Types are supported by EDM™ catalogs. When these component types are selected, a Catalog Selection dialog appears enabling the user to select the component. The Auto Catalog Select command defines if a catalog is automatically opened when the Section Type is selected. By default, the Auto Catalog Select option is active. Alternatively, select the Catalog button for the currently selected Component row.

Component Specific Details Link

Click the Details link to add or modify the details of the currently selected component in the Component's Details dialog.

File Attachment Support ( )

The Components spreadsheet allows for one or more files to be attached to a row in the spreadsheet.

To attach a file to a row in the spreadsheet, left-click the cell in the (Attachment) row and select New.... The Attachment Properties dialog appears that allows the user to attach a document to the cost item. For more information see the Using Attachments in Spreadsheets topic.

MD Top

The MD Top displays the top depth of the component.

MD Base

The MD Base field is calculated by adding the Length of the string component to the MD Top.

Top Set

The Top Set of the component is calculated by adding the lengths of the previous components to the MD Top.

Bit Operations Calculations

Flow Rate

The Flow Rate field is populated by the Pump Operations Output as follows.

Using the last operation entered for each pump, the total Output value is pushed to the Flow Rate in the Bit Operations tab for all types excluding the Slow Pump code.

For example, in Pump Operations you have three pumps as follows:

Pump #1

Pump Operation #1 – Slow Pump – Output = 137

Pump Operation #2 – Drilling - Output = 267

Pump #2

Pump Operation #1 – Slow Pump – Output = 125

Pump Operation #2 – Slow Pump- Output = 110

Pump #3

Pump Operation #1 – Slow Pump – Output = 132

Pump Operation #2 – Drilling - Output = 256

Pump Operation #3 – Circulating - Output = 242

This will update the Bit Operation/' Flow Rate to 509 (last Pump Operation of Pump #1 plus last Pumps Operation of Pumps # 3).

This feature is controlled by the EDM System Setting SlowPumpCode.

P Bit (Pressure Differential)

P Bit is the pressure differential or loss across the bit.

The equation for P Bit and derivation of the coefficient used in the equation are provided below:

Dp = r ´ Q² / (2 ´ C_d² ´ A²)

Where:

Dp = pressure drop across bit (psi or kPa)

r = fluid density (ppg or kg/m³)

Q = flow rate (gal/min or L/min)

C_d = jet discharge coefficient

A = total flow area (in² or mm²)

Note: C_d is a dimensionless coefficient. It may be as high as 0.98, but most resource materials recommend using the conservative figure of 0.95. The following value is used in OpenWells® software for this calculation:

C_d = 0.95

The 2 ´ C_d² factor is integrated into the conversion constant. Therefore, the intermediate calculation is just  r ´ Q²/A². This results in an intermediate result of:

For API: lbs ´ gal/(min² x in⁴)

For SI: kg ´ L²/(m³ x min² x mm⁴)

Therefore for API, convert lbs ´ gal/(min² x in⁴) to psi:

Note:  For the API calculation, convert pounds to a mass by dividing by the acceleration due to gravity. This is the "(lbs²/386.04in)" factor you see in the following conversion.

lbs x gal/(min x in⁴) ´ (231 in³/1 gal) ´ (1min²/3600s²) ´ (lbs²/386.04in )= 1/6016.20779221 psi

Now the denominator (6016.20779221) is multiplied by 2 ´ C_d² to get 10859.2550649.

In SI, convert kg ´L2/(m³ x min² x mm⁴) to kPa:

kg ´ L²/(m³ ´ min² ´ mm⁴) ´ (10-6m6/1L²) ´ (1012mm⁴/1m4) ´ (1min²/3600s²) ´ (1kPa/1000(kg/(m ´ s²))) = 1/3.6 kPa

The denominator (3.6) is now multiplied by y 2 ´ C_d²  to get 6.498

Noz Vel (Nozzle or Jet Velocity)

The calculation of Nozzle Velocity (nozzle or jet velocity) and derivation of the constant used in the calculation are provided below:

v = Q / A ´ const

Where:

v = velocity (ft/s or m/s)

Q = flow rate (gal/min or L/min)

A = area (in² or mm²)

The intermediate result of the calculation is as follows:

For API: gal/(min x in2)

For SI: L/(min x mm2)

Therefore for API, convert gal/(min x in2) to ft/s:

1 gal/(min x in2) x (231 in3/gal) x (1min/60s) x (1 ft/12 in)=0.32083333333333 ft/s

Therefore for SI, convert L/(min x mm2) to m/s:

1 L/(min x mm2) x (0.001m3/L) x (1,000,000mm2/m2) x (1min/60s)=16.6666666667 m/s

HHP (Hydraulic Horsepower)

The calculation of HHP, or hydraulic horsepower and derivation of the constant used in the calculation are provided below:

hp = Q ´ p / const

Where:

hp = horsepower (HP or kW/cm2)

Q = flow rate (gal/min or L/min)

p = pressure drop (lbs/in² or kPa)

const = conversion factor to change (min/in²)/(gal/lbs) to horsepower

The intermediate result of the calculation is as follows:

For API: (gal x lbs)/(min x in2)

For SI: (L x kPa)/min

Therefore for API, convert (gal x lbs)/(min x in2) to HP:

1 (gal x lbs)/(min x in2) x (231in3/gal) x (1ft/12in) x (33000HP/(1ft x lbs/min))=1/1714.28571429 HP

For SI, convert (L x kPa)/min to kW:

1 (L x kPa)/min x (1000(N/m2)/1kPa) x (0.001m3/L) x (1 min/60sec) x (1kW/1000 (N x m/s))=1/60000 kW

Note: Standard API documentation usually rounds this number to 1714. In OpenWells, this calculation is left as precise as possible so that there will be little or no discrepancy between what is calculated for different unit sets.

HHP/Area (Bit Hydraulic Horsepower per Bit Area)

The calculation of HSI, or bit hydraulic horsepower per bit area, is provided below:

HSI = hp / A

Where:

HSI = HHP/in2

hp = horsepower (HP or kW/cm2)

A = total flow bit cross sectional area (in² or mm²)

Impact Force

The calculation of Impact Force is provided below:

Impact Force  = (p / gc) VQ

Where:

Impact Force = measured in lbf

p = Density of Fluid (lb/ft3)

gc = Gravitational constant, 32.17 ft/sec2

Q = Circulation rate (ft3/sec)

V = Velocity through the bit (ft/sec)