W. B. Bradley
BP Research
Houston
D. Jarman
BP Exploration Operating Co.
Aberdeen
R. A. Auflick, R.S. Plott
BP Exploration Operating Co.
Houston
R. D. Wood
BP Exploration Operating Co.
London
T. R. Schofield
BP Exploration Operating Co.
Beijing
D. Cocking
BP Exploration Operating Co.
Ho Chi Minh City
A task-force approach to stuck pipe has produced more than a 70% reduction in BP Exploration Operating Co.'s worldwide stuck-pipe costs during 1989 and 1990.
We believe that these results have been primarily due to focusing our attention on improving personnel performance rather than to the introduction of new technology.
Key elements in this effort involved:
- Recognizing the importance of the drilling contractor and the service company staff's role in helping control stuck pipe
- Promoting a rig-team approach to tackling the problem
- Providing training on rig-team, stuck-pipe problem solving
- Raising awareness of stuck pipe through a coordinated worldwide communications program among BP, contractors, and service companies.
STUCK-PIPE COSTS
Stuck pipe is a major drilling trouble cost for BP and for the industry. Historically, BP's stuck-pipe costs have exceeded $30 million/year, and various estimates indicate that the industry's stuck-pipe costs exceed $250 million/year.
Fig. 1 shows our stuck-pipe costs for the years 1985-88. These costs were compiled from the records of over 700 wells. Also shown is the average stuck-pipe cost per well. For this period, the average stuck-pipe cost was $170,000/well.
From the period 1985-88, 98 wells were selected for a detailed analysis of each stuck-pipe occurrence.
Table 1 breaks down stuck pipe by type of sticking for North Sea and Gulf of Mexico wells. For the North Sea wells, 29% of the total cost was due to differential sticking and 70% was attributed to mechanical sticking.
Note that almost 50% of the costs were due to the hole becoming packed off.
In the Gulf Coast, differential sticking was the dominant cause accounting for 61% of the total cost. Packing off was the other major source of trouble, accounting for 34% of the cost.
Table 2 shows the distribution of stuck-pipe incidents by the type of operation under way when the pipe became stuck. Becoming stuck while tripping accounted for about 50% of all the stuck-pipe incidents, while another 40% occurred while the pipe was stationary. Only about 10% of the incidents of stuck pipe occurred while on bottom drilling.
TASK-FORCE APPROACH
Efforts to reduce stuck pipe are not new in BP. Steady progress has been made in the past by operations and by research and development efforts.
The purpose of the task force was to bring extra focus to further accelerate the reduction of BP's stuck-pipe costs. The goals of this effort were to:
- Have our drilling and contractor staffs know and consistently use all of the industry's expertise on the prevention and cure of stuck pipe
- Accelerate the transfer of technology to operations
- Quickly implement our new findings and ideas into our normal operating practices.
The task force was formed in early 1989 and included key staffs from each of our three regional operating companies and from BP Research. Wide participation by staff was encouraged. The number of authors to this article is indicative of the broad involvement and contribution to this effort.
Early on, the task force identified a number of ideas that we wanted to concentrate on to quickly reduce our stuck-pipe costs:
- We felt that improving stuck-pipe prevention would produce greater cost reductions than improving methods to free the pipe once it became stuck.
- If we were going to reduce stuck pipe, we would need to include the drilling contractor and service companies. It was clear that we could not do it alone.
- The day-to-day prevention of stuck pipe is largely in the hands of the rig-operations team. The driller is a key member of that team.
- Each member of the rig team has an important contribution to make in controlling and solving stuck-pipe problems.
With the above thoughts in mind the task force developed and implemented a program of action that included four main thrusts:
- A detailed analysis of past stuck-pipe incidents
- The development of a stuck-pipe awareness campaign
- Improvement in the transfer of our stuck-pipe technology to the rig-operations team
- The development of improved methods to warn the driller of impending stuck pipe.
The analysis included a review of overall stuck-pipe costs to determine if any major trends were evident and a detailed study of 98 wells to understand what the principal causes of our stuck pipe were. This allowed us to focus our resources on the main targets of opportunity.
AWARENESS PROGRAM
To effectively communicate the stuck-pipe message to our worldwide drilling, contractor, and service company staffs, the task force chose to:
- Create and distribute a monthly cartoon message
- Run periodic stuck-pipe competitions to challenge staffs on their knowledge of stuck pipe. A prize was awarded to each person who successfully completed the competition. Both the monthly cartoon messages and the competitions were provided to all rigs and offices of contractors drilling for BP worldwide. The same applied to all of our drilling offices.
A typical cartoon is shown in Fig. 2. As a central character to highlight what can go wrong, a species of gremlin known as a "Stuckpiper" was invented and used in each of the cartoons.
TECHNOLOGY TRANSFER
An important early objective of the task force was to produce practical guidelines on how to avoid stuck pipe. By drawing on the expertise within BP and the industry we developed a compact 32 page handbook outlining the principal mechanisms of getting stuck and guidelines on how to avoid them.
To date, this BP publication has been distributed to over 1,300 BP and contractor staffs. The guidelines have been translated into Spanish and French to ensure the widest possible dissemination of this information to the rig teams.
A second objective of the task force was to develop and present a 2-1/2-day course on the guidelines aimed at the whole rig team. Each class was designed to include a representative team including a BP rig representative, a BP drilling engineer, a tool pusher, a driller, a mud engineer, and a mud logger.
Besides presenting the material in the guidelines, the course was constructed to emphasize the need for close cooperation and good communication within the rig team to successfully combat stuck pipe.
This was accomplished by presenting the course as a series of practical drilling problems that the team members solved together. This illustrated the expertise each member could bring to the successful solution of the problems. The course has been presented both in English and Spanish.
STUCK-PIPE WARNING
From the analysis of past stuck-pipe incidents it was clear that improved detection and warning of developing stuck-pipe problems would be of major help to the rig team in preventing many serious stuck-pipe problems.
As a result, a research and development project was started to review existing industry warning capabilities. Out of this effort two industry Drilling Engineering Association (DEA) projects were sponsored to develop a better understanding of stuck pipe in the Gulf of Mexico and in the North Sea. Efforts are ongoing.
PROBLEM ANALYSIS
The detailed analysis of a sample of 98 stuck-pipe wells from our overall stuck-pipe data base revealed a number of things. One of the most important findings was the strong correlation between the incidents of stuck-pipe and the crew shift change handover times.
Fig. 3 shows the results of plotting these 98 incidents of stuck-pipe as a function of when they occurred during the day. The graph is broken into three groups of 0-2 hr (2 hr before to 2 hr after shift change), 2-4 hr, and 4-6 hr.
With two shift changes per day these three groupings cover the full 24 hr period. Note that in the two periods away from the handover times (2-4 and 4-6 hr) there were an average of 21 incidents per period, while the 0-2 hr period had 56 stuck-pipe incidents.
If we assume that 21 incidents represent the number of stuck-pipe events that occurred without the effect of the handover process, then the impact of handover in the 0-2 hr period on stuck-pipe amounts to an increase of 35 incidents or 36% of the total stuck-pipe incidents. That's an increase in stuck-pipe frequency of over 2-1/2 times during this critical period.
We also observed an increased number of stuck-pipe events occurring around the time of crew change out. We believe that this strong correlation between stuck pipe and the handover process offers a clear area of opportunity for improving our stuck-pipe performance.
Several other findings from this analysis are also worth noting. First, we were able to confirm the positive effect of top drives on controlling stuck pipe. With a top drive, the time required to free the drillstring once it becomes stuck was less than the time required with a kelly drive.
The average cost of a stuck-pipe incident with a top drive was one third the cost of an average incident on a kelly equipped rig.
We also found that the failure of back-off and severance charges was unacceptably high. Failure of a majority of the charges to back-off or sever on the first try was a common feature on the cases that were studied. This is an area that is in need of study and would be a good candidate for an industry-supported project.
COMMUNICATIONS
A strong emphasis on a communication program to make people more aware of stuck pipe has, we feel, been a key element in the success of this project.
During 1990 we began supplying monthly cartoons to rigs worldwide (on average to about 35 locations) and to BP and contractor offices. Messages that have been communicated by the monthly cartoons have included:
- Stuck pipe is an important and ongoing problem.
- Despite the fact that we drill a lot of hole, stuck pipe is not inevitable.
- Each person has a part to play in controlling stuck pipe--each person can make a difference.
- Drilling practice messages are made available on hole cleaning, tripping, over-pull, bottom hole assemblies, etc.
Feedback has been positive. In fact, one of our contractor's staffs in Papua New Guinea composed and sent us an unsolicited poem which we later used in one of our monthly cartoons.
So far we have completed two competitions to challenge BP, contractor, and service company staffs on their knowledge of stuck pipe.
The first competition tested their knowledge on the material that was contained in the Stuck Pipe Guidelines. This competition produced 930 winners out of more than 1,300 entries.
The second competition was designed to be more difficult but still produced a large response of 1,100 entries and 750 winners.
It required a team solution to a practical drilling situation which ended with the pipe becoming stuck. The problem was portrayed on a video tape and each team was asked a series of questions on what happened and how would they have changed the operation to prevent the pipe from becoming stuck.
We have recently begun to use the cartoons and competitions to target specific areas and particularly difficult wells. Some of the monthly cartoons have been translated into other languages to better target local crews.
GUIDELINES
One of the results of this analysis showed that, after the fact, the reason for sticking the pipe was clear. This strengthened our view that we must get the existing knowledge on the control of stuck pipe both known and consistently used in our operations.
Both the guidelines and the rig-operation stuck-pipe awareness course were focused on meeting this need. We have held over 20 of these courses in Scotland, the Gulf of Mexico area, Alaska, Norway, and Colombia.
Overall, more than 200 people have attended. More than 75% have been contractor and service company staffs.
Response by attendees to these courses has been good. Surveys taken at the completion of each course have singled out that the team solution method of controlling stuck pipe was the most important message that the attendees got and planned to take away and apply on their rigs.
LESSONS LEARNED
When the task force started, we thought that the principal gains would be made by providing new technology to control stuck pipe. What we found is that most of the gains, to date, have had more to do with people.
The attention placed on unleashing each individual's expertise and the emphasis on team participation in controlling stuck pipe has, in our opinion, been the main reasons for the dramatic reduction in stuck-pipe costs that we have seen.
The results to date of the task-force efforts are both gratifying and a little surprising. The lowering of our stuck-pipe costs occurred more quickly and to a greater degree than we had anticipated. The results are due to the efforts of our drilling, contractor, and service company staffs worldwide, and are a real credit to their active interest and skill.
The results for 1989 and 1990 are shown in Fig. 1. Note that both total stuck-pipe costs and average stuck-pipe cost per well have been significantly reduced.
Promoting stuck-pipe cost reduction to the field began in mid-1989 with the distribution of the Practical Guidelines for Preventing Stuck Pipe to all drilling and contractor staffs as well as to BP.
Fig. 1 shows that by the end of 1989, total stuck-pipe costs were down by 30% and average stuck-pipe costs per well were decreased by 50%. This resulted in a 1989 savings of approximately $10 million.
In 1990, with the task-force program in full swing, costs continued to drop, Based on extrapolating the first three quarter's results to full year costs, total stuck-pipe costs and average stuck-pipe costs both showed a drop of over 70% from the averaged 1985-88 results.
These results are all the more important when one considers that they came on top of already good drilling performance.
The 1985-88 stuck-pipe costs represent only 3-5% of our total drilling costs. Therefore, we are attacking the tail end of the problem, and getting the last bit of improvement is always more difficult than eliminating the first part of the problem.
We are now applying these lessons to other areas of drilling, such as well control and safety, with the expectation of similar improvements.
We have also been approached by a number of other companies about sharing our awareness program and our stuck-pipe rig-operations course with them.
Finally, we believe that the stuck-pipe problem will not go away and stay away without constant attention to it. As with safety, vigilance has to be maintained to ensure that hard won, high standards are not allowed to erode through familiarity.
And as new technology becomes available, we will be able to drill more aggressively and at the same time control stuck-pipe costs.
ACKNOWLEDGMENTS
The authors would like to thank BP's drilling, contractor, and service company staffs for their contributions to this effort. We would also like to note Ian Pitkethly's contributions to the development and running of the awareness program. Finally, we would like to thank BP for allowing us to publish this article.
Copyright 1991 Oil & Gas Journal. All Rights Reserved.