Optimizing The Drilling Process When Using MPD Techniques In Deep Water Applications

2020 ◽  
Author(s):  
Randy Lovorn ◽  
Andrew McLennan ◽  
Brian Grayson ◽  
Isabel Poletzky
Keyword(s):  
2021 ◽  
Vol 73 (02) ◽  
pp. 44-44
Author(s):  
Michael H. Weatherl

Drilling automation and innovation continue as dominant trends despite market downturns and unprecedented challenges in the past year. In many ways, the drive toward new efficiencies and step changes in well-construction performance has taken on an even greater sense of urgency. Further advancements in automation and innovation in well construction are recognized globally as keys to unlocking new opportunities in the ever-changing world in which we live. OTC Live sessions in late 2020 included a fascinating session titled “Opportunities and Challenges in Frontier Basins and Emerging Offshore Areas.” Despite pandemic-induced uncertainty, a significant number of high-impact exploration efforts, including projects in deepwater Gulf of Mexico, Brazil, west Africa, the Mediterranean, and Asia were ongoing. Panelists agreed, given world population and energy consumption being forecast to grow 20% by 2040, that increased hydrocarbon supplies, in addition to renewables, are essential to meeting future demand. The discussion also highlighted increased emphasis on carbon footprint reduction. Leaders from Shell, Expro, Wood Mackenzie, and others spoke to a CO2-intensity/barrel of oil equivalent chart comparing relative values for deep water, unconventionals, oil sands, and liquefied natural gas. It is noteworthy that deepwater production represents the lowest carbon footprint of all hydrocarbon sources by a significant margin. This advantage, combined with the potential for large resource size, high flow rates, and low well count, suggest that deepwater assets will compete in long-term portfolios for many operators. Referring to the current selection of SPE drilling-related manuscripts, automation of land rigs within onshore unconventional basins remains a widely published subject. More specifically, automation of the directional drilling process continues to yield improvements in performance and efficiency. It is often noted that well costs have been reduced by more than 50% with advancements related to horizontal technology, digitalization of well construction, and rig automation. These technologies were largely initiated within onshore, unconventional projects, but application is now wide-spread for offshore, complex wells. Selected papers in this feature are chosen to highlight the latest achievements and near-term opportunities across the full spectrum of upstream projects. A consistent message from paper SPE 203251 regarding drilling automation in the digital age reads, “industry has yet to benefit on a large scale from these advancements and…significant value remains untapped.” This reoccurring theme appears across operator and geographical boundaries, revealing significant opportunity and the need for ongoing emphasis. Software and hardware evolution progresses along with more- comprehensive integration of rig equipment and functionality. Industry now is more focused on moving from automation of individual tasks toward automation of the full well-construction process from plan to completed borehole. This idea is presented in paper SPE 201763. Change management remains a key issue within the process to ensure adequate control, early buy-in from stakeholders, and strong leadership. In summary, impressive examples of ongoing innovation span domestic unconventional plays, remote/international locations, geologically complex thrustbelt fields, and deep water with managed-pressure drilling in narrow pore pressure/fracture gradient environments. The few selections that appear here are a reflection of many more published by SPE in the past year and are a powerful testament to the ingenuity and perseverance of those involved.


2021 ◽  
pp. 1-35
Author(s):  
Jin Yang ◽  
Shujie Liu ◽  
Huanhuan Wang ◽  
Xu Zhou ◽  
Yu Song ◽  
...  

Abstract A large numbers of deep-water drilling practices have shown that more than 60% of deep-water wells have the complex leak-off during the drilling process, which poses great difficulties and challenges for the safety and operation time of deep-water drilling. The purpose of this article is to establish a method for predicting the fracture pressure in shallow formations. In this study, the deep-water shallow formation was divided into the upper unconsolidated soil layer and the lower diagenetic rock layer according to the geotechnical distribution characteristics of the deep-water shallow formation. The location of the transition soil/rock layer zone was determined using the upper soil layer density trend line and the lower rock layer density log data regression trend line. The deep-water shallow fracture pressure prediction model was established based the soil/rock transition zone. Shear failure criterion was used above the transition zone and tensile failure criterion is used below the transition zone. The shallow fracture pressure of 6 drilled exploratory wells in the X block from the South China Sea were calculated using this new method and the calculation errors were all less than 3.18%. Moreover, the shallow fracture pressure body in this block was established using the Kriging interpolation method based on 6 drilled exploratory wells data. This shallow fracture pressure body established here were used to predict 9 development wells shallow fracture pressure with a predictive error less than 1.7% and there were no drilling accidents. The case study demonstrates that the new model can significantly improve the prediction accuracy, has good prospects for popularization and application.


1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.


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