Drilling Time Follow-up with Non Productive Time Monitoring

Author(s):  
Tuna EREN
2021 ◽  
Author(s):  
Dmitri Gorski ◽  
Martin Kvernland ◽  
Knut Hals ◽  
Margrethe Blaaflat ◽  
Johannes Ladenhauf ◽  
...  

Summary A novel method of utilizing simulations of surge and swab induced by floating rig heave is presented in this paper. The intended applications are in well planning and follow-up of drilling and completion operations. We focus on rig heave during drill pipe connections when the rig's heave compensator cannot be engaged. The method consists of: (1) estimating a dynamic, well- and operation-specific, rig heave limit based on surge & swab simulations at different depths in a well and (2) clearly communicating the dynamic rig heave limit to the rig crew and onshore organization as a simple metric. We present cases where this novel methodology has been tested during the drilling and completion of two offshore wells in Norway, and we elaborate on the operators’ view of the method's advantages. We conclude that complementing the traditional fixed rig-specific heave limit with the dynamic one that is based on the properties of the actual well and the actual drilling/completion parameters offers an opportunity to improve management of risks related to breaching well pressure margins or damaging downhole equipment and to reduce costs through reduction of weather-related non-productive time. We show that the dynamic rig heave limit may differ significantly from well to well and also throughout the same well depending on the kind of operation in the well, depth in the well, well geometry and other parameters related to well and operation properties. Our conclusion is that care should be taken when generalizing a maximum allowed rig heave value as is the industry practice today. The benefits of utilizing dynamic well-specific rig heave limit should be assessed during well planning for any well drilled and completed from a floating rig. Well planning software existing today does not offer this functionality.


2020 ◽  
Vol 26 (5) ◽  
pp. 47-63
Author(s):  
Aows Khalid Neeamy ◽  
Nada Sabah Selman

Many problems were encountered during the drilling operations in Zubair oilfield. Stuckpipe, wellbore instability, breakouts and washouts, which increased the critical limits problems, were observed in many wells in this field, therefore an extra non-productive time added to the total drilling time, which will lead to an extra cost spent. A 1D Mechanical Earth Model (1D MEM) was built to suggest many solutions to such types of problems. An overpressured zone is noticed and an alternative mud weigh window is predicted depending on the results of the 1D MEM. Results of this study are diagnosed and wellbore instability problems are predicted in an efficient way using the 1D MEM. Suitable alternative solutions are presented ahead to the drilling process commences in the future operations.


2019 ◽  
Vol 290 ◽  
pp. 10003
Author(s):  
Ion Foidaş ◽  
Dan-Paul Ștefănescu ◽  
Mihai Serbancea

Mankind’s increased requirement for and dependence on energy resources, including the resources resulting from discovery and development of new hydrocarbon commercial reservoirs involves the use of new technologies such as optimization of the drilling process by reducing the non-productive time, the costs and the risks. Casing while drilling involves elimination of classical drilling string by using the casing string both for transmission to the bit of the mechanical energy and for circulation of drilling fluid into the well. Although there is a number of technical or perception barriers related to the use of casing drilling, the important benefits of this technology related to reduced drilling time and problems associated to the drilling string make it an increasingly viable alternative to conventional drilling. The experience in applying this technology has proven that it can reduce the time of well execution and sometimes it lowers the costs in relation to drilling depth.


2020 ◽  
pp. 18-25
Author(s):  
A. D. Bakirova ◽  
D. V. Shalyapin ◽  
E. V. Babushkin ◽  
D. L. Bakirov ◽  
V. G. Kuznetsov

The maintenance safety of the wellbore in clay-claystone formations is important aim for modern investigations for companies in Western Siberia as usual. There is a lot of non-productive time to do sidetrack due to weak clay rocks. The analysis was done to solve these true challenges of the sidetrack into the different production zones. There is a lot of non-productive time for the accident responses because of wellbore lose control. For example, 50 % of drilling time has non-productive time to stabilize wellbore. There are the most effective ways to prevent losing control of wellbore: control of mud density and pressure drop variation, using of inhibitors with high effectivity, applying stabilizing bath in dangerous zones.


2021 ◽  
Author(s):  
Maria Retuta ◽  
Leiro Medina

Abstract Differentiating wellbore breathing from real influxes in Alberta's Deep Basin has been problematic in the past as they both result in similar surface parameters. An incorrect interpretation of formation breathing may lead to significant non-productive time (NPT) as secondary well control operations from an influx can take days. On the contrary, a false negative will force drillers to perform secondary well control procedures that may lead to loss of circulation if excessive and unnecessary pressure is exerted on the formation. MPD allows for a systematic approach to identify wellbore breathing more accurately in gas wells. The process involves a series of consecutive pressure build-up and flowback tests with close real-time monitoring to identify a breathing formation that is returning fluid to surface as microfractures close. This paper describes the protocol designed for distinguishing wellbore breathing and illustrates how several drilling parameter trends were interpreted to correctly identify wellbore breathing characteristics and differentiate them from a migrating gas influx. Testing the procedure on multiple wells resulted in 70% operational time savings from reduction in post mud rollover delays on breathing wellbores. This paper shows that the methodology utilized provides consistent and effective results using the MPD techniques, eliminates the ambiguity of wellbore breathing versus actual influxes, and shows the potential application in more areas that are prone to this problem, reducing uncertainty, NPT, and total drilling time.


2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.


1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.


Author(s):  
D.G. Osborne ◽  
L.J. McCormack ◽  
M.O. Magnusson ◽  
W.S. Kiser

During a project in which regenerative changes were studied in autotransplanted canine kidneys, intranuclear crystals were seen in a small number of tubular epithelial cells. These crystalline structures were seen in the control specimens and also in regenerating specimens; the main differences being in size and number of them. The control specimens showed a few tubular epithelial cell nuclei almost completely occupied by large crystals that were not membrane bound. Subsequent follow-up biopsies of the same kidneys contained similar intranuclear crystals but of a much smaller size. Some of these nuclei contained several small crystals. The small crystals occurred at one week following transplantation and were seen even four weeks following transplantation. As time passed, the small crystals appeared to fuse to form larger crystals.


Author(s):  
C. Wolpers ◽  
R. Blaschke

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.


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