The Ultimate Well Control Kill Sheet program
The “Ultimate Well Control Kill Sheets” (UWCKS) program is a new innovative and advanced well control kick sheet program which automatically calculates the drill pipe pressure step down graph for vertical, deviated and horizontal wells with up to 5 drill string sizes. It is innovative as this has never been done before in the oil industry. The UWCKS was developed by Frank French C Eng FIMMM (link to LinkedIn profile) Blair Field Services Ltd.
The oil industry currently only has kill sheets for vertical and simple deviated wells which have one size of drill pipe.
The biggest mistake in most “in house” developed vertical kill sheet programs is they design them to be used for multiple sizes of drill pipe in the volume calculations but do not take into account the impact of multiple sizes of drill pipe on the calculated drill pipe pressures. They normally use a use a straight line from ICP to FCP (Blue line in graph below). This only works for a single drill pipe string. If there are multiple drill pipe sizes then the well will go underbalance and start to flow when pumping the kill mud down the drill string.
A complex well is any well which has more than one size of drill pipe or has more than one build or drop section.
The graph below shows this problem where the dotted red line is the correct (true) drill pipe pressure step down graph for a vertical well with two sizes of drill pipe.
If the blue line (straight line from ICP to FCP) is followed then the well will go underbalanced leading to a completely compromised well kill operation when pumping the kill mud to the bit.
The green line shows the correct (true) drill pipe pressure step down graph for a highly deviated well.
If well deviation is not taken into account for a highly deviated / horizontal well and a simple straight line from ICP to FCP is followed (blue line) then the bottom hole pressures will be significantly greater than required to maintain bottom hole pressure constant for well kill operations. This can lead to exceeding the fracture gradient of the formations leading to an underground blowout and a completely compromised well kill operation.
The calculations required to perform a well kill operation on highly deviated / horizontal wells and wells with multiple sizes of drill pipe is not taught at well control schools.
Stena Drilling recognised that holding casing pressure constant when pumping kill mud to the bit is potentially very dangerous. Stena Drilling’s well control policy was “that a drill pipe pressure step down graph shall be used when pumping kill mud to the bit during the Driller’s second circulation”. The problem was that the industry only has kill sheets for simple wells with one size of drill pipe and Stena Drilling use up to five different sizes of drill pipe in their drill strings.
The “Ultimate Well Control Kick Sheets” (UWCKS) program was developed for Stena Drilling so they could meet their well control policy.
Stena Drilling have been using the kick tolerance calculator and new kill sheet program software for all of their rigs for the last 3 years. Click on link to see Stena Drilling’s LinkedIn post.
The software has been designed to improve how well control operations are performed on a number of levels.
It has been designed to be easy to use for the rig crews. The software performs all of the calculations. The rig crew only need to input well data which they are very familiar with. It is so easy to use that only a 1 hr training session was required to train Stena Drilling’s personnel to use it (Assistant drillers to Rig Managers).
If you are interested in purchasing the Ultimate Well Control Kick Sheets program then please email blairfieldservices@btinternet.com
The UWCKS program will work on any PC or Laptop which uses Microsoft Office software. The UKTC will not work on Apple Mac computer systems.
The advantages of using the new kill sheet program are: –
- The UWCKS program provides a step change in kill operations safety as it allows drill pipe pressure to be used during kill operations for all well designs. This has never been done before in the industry.
- The UWCKS provides an alternative method for killing complex wells which allows drill pipe pressure to be used to pump the kill mud to the bit. This eliminates the risk of getting into an uncontrolled well control situation when using casing pressure to control the well, as currently exists with the traditional Driller’s 2nd circulation.
- The UWCKS produces a drill pipe pressure step-down graph / table for all well designs from vertical, simple deviated, complex deviated, horizontal wells, with up to 5 sizes of drill-pipe, 10 casing / liner annular capacities and 7 open hole annular capacities.
- The UWCKS automatically produces the drill pipe pressure step down table at the step interval specified by the user. This significantly improves the management of well kill operations. The choke control operator knows exactly the pressure required to be held on the drill pipe at the stroke interval specified by the user without having to scale the numbers off a step-down graph.
- The UWCKS is an easy-to-use kill sheet and has been designed for the man on the rig. The user only has to input the well data and is not required to do any of the calculations.
- The UWCKS is a sophisticated kill sheet. There are a number of validation checks to ensure that the user inputs the data correctly. If the data is not input correctly then the program alerts the user to any issues.
- The UWCKS saves the rig team significant amounts of time every day as it is so easy and quick to fill out the kill sheet. The Toolpusher no longer has to check all of the calculations in the Assistant Driller’s kill sheet which can take up to an hour/shift.
- The UWCKS program is safety critical software. The program is encrypted so the user cannot modify or change the program. The program provides a standardized kill sheet that can be used throughout the company.
- The UWCKS program has been produced in API, Mixed (metric depth) and Metric units. It can be produced in any unit combination required by the client.
- The UWCKS has a proven track record and has been used by Stena Drilling on their 6 rigs for 3 years.
Frank French has also developed an advanced risk based Kick Tolerance Calculator program which can be viewed at www.kicktolerance.com.
An example of the UWCKS W & W drill pipe pressure step down graph for a horizontal well with 2 sizes of drill pipe is shown below (blue line) compared to the IWCF kick sheet calculations for a deviated well (orange line).
UWCKS (blue line) compared to IWCF kill sheet numbers for a deviated well (orange line)