Abstract: The social cost of offshore well plug and abandonment (P&A) is extreme and could escalate by 150% to 354%.  “UK taxpayers are facing a £24 billion bill for decommissioning that threatens to wipe out the remaining value of UK North Sea oil and gas according to the Financial Times.  About 47% of decommissioning costs are well plug and abandonment, so over £11 billion is attributable to well P&A.  Well P&A is, literally, putting cement into a hole-in-the-ground, so why is it so expensive?  The majority of that £11 billion cost is not for cement plugging of the wells but, instead, relates to the systematic selection of the most expensive, instead of the least expensive, offshore logistics.  This fact is easily demonstrated by comparing relatively inexpensive “onshore P&A” to very expensive “offshore P&A,” for similar well architectures.  Many industry proven offshore logistical alternatives exist; however, industry systematically selects the most expensive offshore logistical means for well P&A.  Proponents of drilling rigs, which account for 40% to 70% of construction and P&A costs, cite cement bond measurements and keeping risks as-low-as-reasonably-practical (ALARP); however, measuring the cement bond is regularly avoided during drilling rig P&A and quantitative risk assessment shows that lower cost well logistics, using fewer people protected by pressure containment systems, are safer.  To explain this conundrum to those financially authorising drilling rig P&A requires ordinary speech to avoid the confusing technical jargon of practitioners.  With those terms of reference in mind, Oilfield Innovations Limited, a Scottish registered micro-company, seeks funding to qualify a safer and lower cost universal rigless P&A method that uses lower cost industry proven tooling and offshore production intervention logistics, combinable with the logistics of other decommissioning activities, to reduce P&A cost by 32% to 60% and put cement into a hole-in-the-ground according to present regulatory requirements and industry best practice so as to keep risks and legal liabilities as-low-as-reasonably-practicable.  Download the article to read more.

Oil and gas wells are comprised of multiple concentric conduits that must be cut and removed during drilling rig plug and abandonment (P&A).  While rigless pulling and jacking units may remove casings and conductors on platforms, rigless subsea P&A must perforate through tubing and casing to isolate annuli.  Rigless P&A could greatly benefit from thru-tubing multi-conduit severance and thru-tubing casing milling within both platform and subsea P&A operations. Conventional downhole cutting technologies generally pertain to precisely severing a single tubular wall and pulling casings one-at-a-time or abrasive fluid jetting severance of multiple conduits simultaneously.  Also, sections of casing can be milled to provide access to larger casings that may be cut using knife blades to allow multiple conduits to be pulled out of the well simultaneously.  Conventionally, cutting through multiple conduits simultaneously uses sand blasting technology that directs a rotated fluid jet of abrasive particles, wherein deployment of the jetting equipment typically requires tubing removal. Various coiled tubing jetting applications have been used for jetting holes through multiple casings, but non-aqueous thru-tubing rigless tools for severing tubing and casings simultaneously do not exist. Rigless P&A would benefit from thru-tubing severance of multiple conduits, so Oilfield Innovations have patented an abrasive filament cutter which functions like a garden strimmer that rotates diamond wire filament to sever tubing, control lines and casing simultaneously. When a diamond wire filament cutter is combined with vertical tubular cutting it can turn tubular walls into confetti-like debris that falls downward to accomplish a scope of work similar to casing milling.  Tubular severance and casing milling are critical parts of well operations, especially P&A, wherein a diamond wire filament cutter could improve efficiency and lower cost by displacing drilling rigs from P&A where it is necessary to mill or cut through multiple casings to place P&A plugs.

Current logging technology is not able to log through multiple casings and the legal liability of potential P&A leakages drives a need to measure the quality of in situ cementation.  Vibration of unsecured tubing within casing prevents conventional cement bond logging tools from accurately sending and receiving acoustic pulses.  Securing the tubing by spiking it to the casing prevents such vibration and connects transmitters and receivers of acoustic logging signals with the casing to measure bonding of in-situ cementation. According cement bond logging can occur both before and after setting a P&A plug.  Download this PDF to read more.

Horizontal physical modelling of the compaction of 2 3/8” 4.7 pound per foot tubing within 5 ½” 20 pound per foot casing yielded a 46% compression ratio within three (3) separate tests, wherein the tubing occupied 54% of its original axial length after it was crushed within the horizontally placed casing.  A number of nuisances regarding tubing crushing were discovered. Point loading of the crushing piston and friction within a horizontal bore were found to be significant factors.  Modelling also indicated that the displacement rate of the pump used was important as additional fluid displacement can compensate for minor leakage about the piston.  In summary, six (6) model runs provided sufficient information for planning of vertical modelling and well testing of Oilfield Innovations’ patented process to achieve rig equivalent wireline and/or slickline well abandonment, whereby the crushing of tubing within casing can provide space for logging casing cementation and provide a rig–equivalent unobstructed cement abandonment plug.  Download this article to read more.

Modern technology is only capable of recovering 10% to 50% of the original hydrocarbons from an oil and/or gas deposit. Consequently, abandoning a well comprises sealing in the remaining 50% to 90% of the hydrocarbons within the containing cap rock for later extraction by our grandchildren and our grand-children’s grandchildren, who will have access to more advanced technology. For example, the North Sea Argyll Field was discovered in 1971 and produced 72.6 million barrels from 1975 to 1992 when it was abandoned. Argyll was then redeveloped and produced an additional 5.2 million barrels from 2003 to 2005 when it was abandoned again. Now, it is being redeveloped yet again with new technology estimated to recover 21-33 million barrels.  Poor well abandonment prevents any future redevelopment of old fields with new technology.  Download this article to read more.

Oil and gas well plug and abandonment (P&A) operations, particularly subsea P&A, is expensive and can take rigs away from more productive exploration and development work.  Suspension and abandonment operations can also impact our environment through their carbon foot print and by bringing pollutants, like naturally occurring radioactive material, into our environment. In response to the high cost, waste, and environmental issues surrounding suspension and abandonment, Oilfield Innovations Limited has developed a cheaper, safer, and more environmentally friendly wireline method, which could displace drilling rigs and pulling units from the vast majority of offshore and subsea well suspensions and abandonments.  Download this article to read more.

The goal of cutting well costs by 30% to 50% is not new and has been recited by countless people who have never delivered for various reasons, including: ● inefficient interfaces between Operators who do not invest in new technology and Service Companies who don’t benefit from developing new technology, ● resistance by a workforce who fear redundancy comes with change, ● extremely low risk tolerances and ● fear of Health, Safety and Environmental (HSE) litigation.  Also, “radical” changes to a system of well construction that uses standardised equipment which has been developed and optimised over a hundred years is not realistically possible in the short term.  Accordingly, new technology solutions usable to cut well costs by 50% require maintaining current HSE risks while using a workforce resistant to change within a market controlled by Service Companies and Operators who neither cooperate nor want “radical” changes.  Effectively, you need a widget that will, like magic, cut the cost of a well by 50% without any significant changes to the current system. The above reasons have not stopped people from trying to reduce cost and, therefore, it is possible that a widget could bridge the gaps between existing technologies to dramatically improve economics. For example, extended reach drilling and multi-lateral well technologies have been developed and field proven precisely for delivering large well cost reductions.  Unfortunately, despite having many of the necessary tools and occasionally attempting multi-lateral wells, Operators have not embraced multi-laterals for very good reasons, which include: Differing Downhole Pressures and a need for Separate Flow Streams, Limited Flow Areas for Conventional Dual String Completions, and Completion Complexity, Intervention Access, Well Barriers and Well Integrity.  The 50% well cost reduction project proposed herein addresses these issues to facilitate widespread usage of proven multi-lateral and extended reach technologies by providing the “missing-link” between Operator’s needs and off-the-shelf technologies. Oilfield Innovations Limited (OILtd) have a “widget,” which we have nicknamed the “Magic Crossover,” that could be the “missing link” joining existing proven technology to deliver a 30% to 50% reduction in the cost of wells.  Before describing our widget, it is important to understand why wide spread usage of multi-lateral technology is limited by existing dual string completion technology.  Download this paper to read more.

Well architecture has evolved over the years, wherein the sizes of casing and conductor have been standardised for yesterday’s hydrocarbons.  Since then, industry has tweaked everything to work around conventional conductor and casing sizes using hole opening, under-reaming, bi-centre bits, decreasing coupling diameters, improving flush joint connects and using higher grades of steel.  All of these work-arounds relate to standardised well architecture sizes, but the next generation of oil and gas development will be more challenging and may need additional adaptations.  Oilfield Innovations’ have patented a new tweak to standardised well architecture that retains conventional casing size standards while providing downhole processing and reducing the need to size-the-hole-down when casing off multiple geologic zones.  The pressure bearing capacity of large diameter pipe is limited because its large diameter walls are more easily expanded or compressed.  The natural properties of steel in large diameter conduits can be strengthen with and intermediate rib when two or more concentric conductor casings are used.  In an offshore environment, shallow geology is easily drilled and larger diameter conductors can be placed.  A substantially larger diameter conventional low pressure conductor can be cemented in place.  Using the weight of the next conductor casing, a smaller large diameter pipe with the ribs can be slide into and cemented within the lower bearing capacity larger conventional conductor to, effectively, double its wall thickness, bending capacity and pressure rating.  Higher pressure surface casing can then be hung within the higher pressure conductor to maintain a larger diameter well architecture.  Additionally, large diameter double and triple walled conductor can be used as a subterranean vertical separator, wherein water production and disposal is a significant issue that prevents development or reduces the life of many marginal offshore fields. Large and heavy above sea level fluid separation equipment requires a relatively large offshore jacket for support, while above sea bed subsea separation is very expensive.  High pressure and bending capacity large diameter conductor-in-conductor arrangements can be used as a vertical subterranean separator and/or a jacket for a monopod that supports low cost disposal of water downhole.  The cost of subsea separation is presently only applicable to prolific offshore fields, whereas a vertical multi-walled well conductor subterranean separator requires only a subsea pump to inject produced water.  Low cost downhole separation could make marginal discoveries economic.  Accordingly, the simple additional of a ribs to a conductor, which slides into and can be cemented within another conductor, can provide the significant benefits of higher pressure and load bearing capacity needed for development of the next generation well architectures.  Downnload to read more.

An LCM Generating Stabilizer tool is designed to slurrify cuttings into LCM size material during drilling, and treat lost circulation, strengthen the wellbore, shear drilling fluids, and aid cuttings removal.  This proposal examines various phases for developing our patented tool, from the designing of a CAD model to software analysis, machining, building, and testing a prototype. A time schedule is presented, which could change based upon the various findings that could arise during development.  These results will guide the tool refinement or re-design.  Download this paper to read more.