The Economics of Coiled Tubing Deployed ESP Completions in the North Sea. A Field Life Cycle Perspective

1996 ◽  
Author(s):  
Juan J. Tovar D. ◽  
Jeffrey S. Callander
Keyword(s):  
Life Cycle ◽  
North Sea ◽  
Coiled Tubing ◽  
The North ◽  
Life Cycle Perspective ◽  
The North Sea

Worlds First Offshore Horizontal Well Using Jointed Pipe Cemented Frac Sleeve Technology

2022 ◽  
Author(s):  
Shaun Thomson ◽  
Baglan Kiyabayev ◽  
Barry Ritchie ◽  
Jakob Monberg ◽  
Maurits De Heer ◽  
...  
Keyword(s):  
North Sea ◽  
New Technology ◽  
Production Performance ◽  
New Developments ◽  
Coiled Tubing ◽  
The North ◽  
New Novel ◽  
The North Sea ◽  
Reservoir Connectivity ◽  
First Job

Abstract The Valdemar field, located in the Danish sector of the North Sea, targets a Lower Cretaceous, "dirty chalk" reservoir characterized by low permeabilities of <0.5mD, high porosities of >20% and contains up to 25% insoluble fines. To produce economically the reservoir must be stimulated. Typically, this is by means of hydraulic fracturing. A traditional propped fracture consists of 500,000 to 1,000,000 lbs of 20/40 sand, placed using a crosslinked seawater-based borate fluid. The existing wells in the field are completed using the PSI (perforate, isolate, stimulate)1 system. This system was developed in the late 1980s as a way of improving completion times allowing each interval to be perforated, stimulated and isolated in a single trip and has been used extensively in the Danish North Sea in a variety of fields. The system consists of multiset packers with sliding sleeves and typically takes 2-3 days between the start of one fracture to the next. Future developments in this area now require a new, novel and more efficient approach owing to new target reservoir being of a thinner and poorer quality. In order for these new developments to be economical an approach was required to allow for longer wells to be drilled and completed allowing better reservoir connectivity whilst at the same time reducing the completion time, and therefore rig time and overall cost. A project team was put together to develop a system that could be used in an offshore environment that would satisfy the above criteria, allowing wells to be drilled out to 21,000ft and beyond in excess of coiled tubing reach. The technology developed consists of cemented frac sleeves, operated with jointed pipe, allowing multiple zones to be stimulated in one trip, as well as utilizing a modified BHA that allows for the treatments to take place through the tubing, bringing numerous benefits. The following paper details the reasons for developing the new technology, the development process itself, the challenges that had to be overcome and a case history on the execution of the first job of its kind in the North Sea, in which over 7MM lbs of sand was pumped successfully, as well as the post treatment operations which included a proof of concept in utilizing a tractor to manipulate the sleeves. Finally, the production performance will be discussed supported by the use of tracer subs at each of the zones.

Underbalanced Coiled Tubing Drilled Horizontal Well in the North Sea

1996 ◽  
Vol 48 (5) ◽  
Author(s):  
Philip Wodka ◽  
Henrik Tirsgaard ◽  
C.J. Adamsen ◽  
A.P. Damgaard
Keyword(s):  
North Sea ◽  
Horizontal Well ◽  
Coiled Tubing ◽  
The North ◽  
The North Sea

scholarly journals New records from the southern North Sea and first records from the Baltic Sea of Kornmannia leptoderma

2019 ◽  
Vol 62 (1) ◽  
pp. 63-73
Author(s):  
Florian Weinberger ◽  
Sophie Steinhagen ◽  
Dmitry F. Afanasyev ◽  
Rolf Karez
Keyword(s):  
Life Cycle ◽  
Baltic Sea ◽  
North Sea ◽  
New Records ◽  
The Baltic Sea ◽  
The Past ◽  
The North ◽  
Green Algal ◽  
The North Sea ◽  
The Baltic

Abstract Combined genetic, morphological and ontogenetic observations show that the circumarctic boreal green algal macrophyte Kornmannia leptoderma has expanded its distribution range into the Baltic Sea, on a German coastal section of 220 km length. The species is also again (or still) established at its former extreme southern distribution limit in the North Sea, the German island of Helgoland, where it has not been detected during the last four decades. Macroscopic visible sporophytes of K. leptoderma are nowadays present in the Baltic Sea and at Helgoland from February to September, while they were in the past only detected from February to May at Helgoland. This capacity for formation of sporophytes in summer correlates with the circumstance that K. leptoderma from the Baltic Sea can complete its life cycle at 15°C while several studies conducted decades ago with material from Helgoland and from Pacific coasts consistently reported an inhibition of the algal gametogenesis at temperatures that exceed 12°C. Possibly K. leptoderma has undergone adaptations that facilitate its spread into warmer environments, unless the Kornmannia present in the Baltic Sea and on Helgoland today represents a newly introduced cryptic species.

Enhancements in Fracturing Fluid Engineering Reawakens a North Sea Giant

2022 ◽  
Author(s):  
Asif Hoq ◽  
Yann Caline ◽  
Erik Jakobsen ◽  
Neil Wood ◽  
Rob Stolpman ◽  
...  
Keyword(s):  
Quality Control ◽  
North Sea ◽  
Large Scale ◽  
High Shear ◽  
Testing Procedures ◽  
Coiled Tubing ◽  
The North ◽  
Track Record ◽  
Enhanced Production ◽  
The North Sea

Abstract The Valhall field, operated by AkerBP, has been a major hub in the North Sea, on stream for thirty-eight years and recently passed one billion barrels of oil produced. The field requires stimulation for economical production. Mechanically strong formations are acid stimulated, while weaker formations require large tip-screenout design proppant fractures. Fracture deployment methods on Valhall have remained relatively unchanged since the nineties and are currently referred to as "conventional". Those consist in a sequence of placing a proppant frac, cleaning out the well with coiled tubing, opening a sleeve or shooting perforations, then coil pulling out of hole pumping the proppant frac. For the past few years, AkerBP and their service partners have worked on qualifying an adapted version of the annular coiled tubing fracturing practice for the offshore infrastructure - a first for the industry, which has been a strategic priority for the operator as it significantly reduces execution time and accelerates production. As with all technology trials, the implementation of this practice on Valhall had to begin on a learning curve through various forms of challenges. Whilst investigating the cause and frequency of premature screenouts during the initial implementation of annular fracturing, the team decided to challenge the conventional standards for fluid testing and quality control. Carefully engineered adjustments were made with regards to high shear testing conditions, temperature modelling, and mixing sequences, these did not only identify the root cause for the unexpected screenouts, but also helped create the current blueprint for engineering a robust fluid. Since the deployment of the redefined recipe, adjusted testing procedures and changes made to the stimulation vessel, there have not been any cases of fluid induced screenouts during the executions. The fewer types of additives now required for the recipe have lowered the cost of treatments and the lower gel loading leads to reduced damage in the fractures, thereby contributing to enhanced production over the lifetime of the wells. This paper describes the investigation, findings and the resulting changes made to the fluid formulation and quality control procedures to accommodate for high shear and dynamic wellbore temperature conditions. It discusses the rationale behind the "reality" testing model and, proves that significant value is created from investing time in thoroughly understanding fluid behaviour in the lab, prior to pumping it on large-scale capital-intensive operations. The study demonstrated that there is always value in innovating or challenging pre-conceived practices, and the learnings from this investigation significantly improved the track record for annular fracturing on Valhall, redefined fluid engineering for the North Sea and will inform future annular fracturing deployments on other offshore assets around the world.

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