CWI Tallybook

Collection of 36 individual calculators in one application. No need to open & close multiple files. Easy to identify links on main page to open the calculation required.

Calculators seperated into 6 easy to identify, scrollable sections.

Each calculator opens in its own window, window can be recalled to screen from taskbar  allowing memory without writing files to your computer.

Fully functional 7day trial. (In app licence purchase).

£15.99 GBP Single Computer Licence.

£34.99 GBP Three Computer Licence.

Blind Box Sizing

This applications calculate the minimum & maximum allowable blind box size to use for boxing off wire at the rope socket during wireline fishing operations.

Includes some guidance on how to interpret the results of the calculation.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Choke Gas Rate Calculation

There are many choke gas rate estimation  equations in use, with varying degrees of complexity of input parameters required. 

This application employs two different estimation methods, one with a known gas gravity & downstream temperature, one without. I've had favouirable results with calculating both equations & giving the customer an estimated rate somewhere in the middle.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Choke Oil Rate Calculation

There are many choke oil rate estimation  equations in use, with varying degrees of complexity of input parameters required. The 'Gilbert' equation is one of the the earliest & most equations that require minimal input parameters are know as 'Gilbert Type Equations'.

This calculator provides an oil rate estimate using both the 'Gilbert' & 'ROS' equations. My experience has been that Gilbert tended to provide slightly lower estimation than was found when acurate rates had been achieved via the well test separator & ROS tended to be slightly higher. I've had favouirable results with calculating both equations & giving the customer an estimated rate somewhere in the middle.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

CO2 Emissions

In many countries, tracking CO2 emissions is now or soon will be compulsary. The main components of hydrocarbons that contribute to global warming are CO2, N2O & CH4, this application uses EEMS emissions factors & global warming potential vaues to calculate the equivalent CO2 emissions from the hydrocarbons consumed. (User will have to obtain the correct factors for the substance consumed, values shown in the screenshot opposite are from a well test).

This application multiplies the the mass of the hydrocarbons burnt by the EEMS Emission factor & GWP value for each component to provide an equivalent CO2 emission value. (Useful during well testing or monitoring engine emissions).

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

CT Reduced Collapse Pressure

As coiled tubing ages, when string tension is applied or when internal pressure is applied to the tubing, the collapse rating stipulated in the tubing manufacturers data may no longer apply & users risk tubing damage if they approach the upper limit of the supplied data. (Limits supplied by the manufacturer is usually based on new tubing with no tension or pressure applied).

This application considers the axial stress & pressure applied to recommend a reduced collapse pressure, the app then provides a recommended safety factor considering the tubing lifespan usage & a new recommended allowable collapse pressure. 

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

CT Stuck Point

Estimates the point at which a CT string may be stuck based on the applied overpull & observed stretch in the tubing string.

Pipe cross sectional area & modulus of elasticity required, (Usually available on the tubing data sheet).

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Differential Pressure from Density

Calculates the hydrostatic bottom hole pressure based on the fluid weights & true vertical depth, applied pressure will be added to give an overall bottom hole pressure.

Tubing & annulus pressures can be calculated on the same sheet & the results will show the pressure differential from tubing to annulus at the depth of interest. Overbalance in the annulus will show as a negative tubing pressure, (overall depth in each side must be equal for this).

Input for four different fluid weights in both tubing & annulus sides should allow fast calculation in most circumstances.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Fluid Level Estimate

Calculates the estimated fluid level in a well based on the tubing head pressure, reservoir pressure, gas & fluid gradients using basic International Well Control Forum, (IWCF), formula.

Where a combination of fluid is expected, an average gradient should be used & results will still be relatively accurate.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Gas BOE and Weight

Calculators to convert from dry or wet gas to barrels of oil equivalent, BOE. Conversions to & from standard cubic feet, cubic meters & barrels. 

Calculator to convert from gas volume to weight in tonnes using the method recommended by the API Compendium of Greenhouse Gas Emissions Estimation for the Oil and Natural Gas Industry - August 2009.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

H2S & CO2 Partial Pressure

Calculates the H2S and CO2 partial pressures based on the anticipated H2S & CO2, wellhead & bottom hole pressures.

Provides some standard guidance on wireline cable &/or completion tubular selection for initial design purposes.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Length Change Due To Temperature

This routine estimates the change in tubing length that may be observed in the completion string due to temperature.

Calculate materials with differing co-efficient of thermal expansion properties seperately. For offshore wells, calculate the length change seperately for tubing below the seabed and in water.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Pressure Test Volume

Uses the volume of the item being pressure tested & the compressibility factor of the test fluid to calculate the additional volume required to acheive the desired test pressure. 

Assumes that the test item has been topped up with fluid before applying pressure & that the test fluid is the same as the fluid contents of the item being tested. Includes some typical oilfield fluid compressabilty factors & the option to use a custom factor where required.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Single String Bullhead Margins

This application calculates the tubing burst limit, formation frac limit & minimum bullhead pressure required to kill a single string, (single tubing size) completed well. (Multi string calculator planned as a future release).

Once calculated the app produces a graph that can be printed and used for reference.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Snubbing Balance Point

When snubbing tubing into a live well, the safest method to cross the balance point is to run the tubing empty, (still in pipe light mode), stop running tubing & close both pipe light & pipe heavy slips, fill the pipe with fluid to cross the balance point then continue running pipe on the pipe heavy slips.

This application calculates the balance point for empty pipe & when full of 

a nominated weight of fluid. The user can then select an appropriate hold depth for crossing the BP. (Assumes calculated depths are still in vertical well section & pipe collapse rating for empty pipe have been checked).

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

SSSV Setting Depth

This application calculates the maximum depth at which a SSSV should be set to prevent a failure to close due to hydrostatic pressure.

If the standard safety margin is considered excessive or insufficient, facility has been provided for user to enter an alternative safety margin and recalculate.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Tank Volumes

Calculation of the total volume of tanks of various sizes & shapes. Also calculates the volume of the fluid within the tank based on the measurement of the fluid level from the bottom of the tank. Enter the fluid weight in ppg & the tare weight to calculate the overall weight of the tank & deck loading requirements, (NOTE: deck loading is base on the surface are of the base of the tank, any transportation frame fitted will change the deck loading & have to be recalculated manually).

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

TVD Between Survey Points

This application calculates a new true vertical depth (TVD) or measured depth (MD) for a depth between two recorded survey points.

Two methods available, one is useful for deviation hold sections & calculates a new TVD or MD based on the deviation at the shallower of two recorded survey points. The second method calculates a new TVD based on the average TVD / MD ft between two recorded survey points, useful for deviation build sections.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Well Volumes

When planning or executing a completion or well intervention operation, considerable time can be spent carrying out multiple calculations manually for different tubing or casing sizes.

Well Volumes provides sufficient input points for most well configurations & allows all the well volume information to be calculated in one go. simply enter the casing / tubing OD's & ID's, start & end depths for each section of interest, click the calculate button & Well Volumes will output the capacity & volumes of each section as well as the total volumes of the tubing, casing & well.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.

Wire Fall Back

This application estimates the depth you should expect to locate the top of the wire after a breakage above the rope socket. The calculation takes the length of the lost toolstring into consideration before providing an estimated depth.

The calculation is based on a fall back factor for a given size of wire in a given tubing size. A table with example fallback factors is shown, however, it is recomended to request specific fallback factors from the wireline provider.

Fully functional 7day trial. (In app licence purchase).

£3.99 GBP Single Computer Licence.

£8.99 GBP Three Computer Licence.