Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B33/00—Sealing or packing boreholes or wells
  • E21B33/10—Sealing or packing boreholes or wells in the borehole
  • E21B33/12—Packers; Plugs
  • E21B33/126—Packers; Plugs with fluid-pressure-operated elastic cup or skirt
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B37/00—Methods or apparatus for cleaning boreholes or wells
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/11—Perforators; Permeators
  • E21B43/116—Gun or shaped-charge perforators

Definitions

• the present invention relates to a method of plugging a petroleum well permanently or temporary, for instance, during a plug and abandonment operation (P&A) or during other operations where setting of a barrier in the well is required, by use of a multitask tool.
• P&A plug and abandonment operation
• Petroleum wells for the exploitation of oil and/or gas from a reservoir normally consist of an upper and outer conductor, which forms the base of the well, an upper casing arranged into and in extension of the conductor, and further down in the well more casings which are arranged into and overlaps the above casing.
• a production tubing string is located in the middle of the well for transporting petroleum from the bottom of the well to the earth ' s surface or to the sea floor. Annul i will then be formed between the different casings.
• Several wells will normally be drilled in a reservoir, where some of these are test wells which are only used for a shorter period prior to the production from the reservoir, and thus will be plugged after testing.
• test well If a test well is a successful well, such a well will normally be temporary plugged before the production starts, while a test well which is "dry " , i.e. a well in which the hydrocarbon content is too small to be worth producing, will be plugged permanently.
• a common requirement during plug and abandonment operations is to have a plug set inside an inner casing string and a further plug set in the annulus between the inner casing string and the outer casing string.
• the plug will then extend across the full cross sectional area of the well and seal both vertically and horizontally in the well.
• setting of a barrier in a well it may be that additional official requirements must be fulfilled.
• the placing of the cement is not conclusive as the cement will have to change place with the annulus fluids present in the annulus prior to placing barrier cement.
• the fluid which is present in the annulus needs to be e v a c u a t e d/ f o r c e d to cither above or below the interval or through the formation rock by formation leak-off.
• the current logging technologies e.g. Ultra Sonic Imager Tool (US IT). Cement Bond Log (CBL), Segmented Bond Tool (SBT). have proven very subjective regarding being able to conclusively confirming or verifying that the barrier is sealing properly in the annulus.
• the current designs of today ' s logging tools are fully dependent on a logging-friendly downholc environment, i.e. the environment needs to fulfill certain demands to be able to perform a proper logging operation.
• Document WO 2012/096580 A 1 describes a method and washing tool for combined cleaning of an annulus in a well across a longitudinal section of the well, and subsequent plugging of the longitudinal section.
• One of the embodiments described in said document includes dropping of the perforation tool subsequent to the perforation of the well, washing the perforated /one. setting the washing tool at a location in the well, and finally cementing in the perforated /one. Additionally, subsequent to that the cement has been introduced in the well, normally remaining washing fluid that has not been displaced during the cementing operation, has to be displaced by pressurizing the cement plug.
• cement plug will not seal off the well properly, as not only the washing fluid will be forced or squeezed out of the tubular and into the surrounding formation, but also the cement. Furthermore, the cement plug will not be subjected to the same pressure over its length, whereby the cement may not be distributed equally around the periphery of the well.
• an objective of the present invention to provide a method of plugging a petroleum well permanently or temporary that is more reliable compared with the solutions described in prior art. More specifically, an objective of the present invention is to provide a solution securing a more reliable and controlled displacement of the fluids, e.g. sealing fluids, present in the annulus in a plug and abandonment operation or in other operations where setting of a barrier in the well is required.
• the fluids e.g. sealing fluids
• Another objective is to provide a method making it possible performing perforation, washing and cementing in a single trip in the well.
• the invention solves at least one of challenges in relation to the prior art solutions, where the cement is placed into the tubular whereafter the cement is pressurized out of the tubular and into the annulus. namely by providing a method that gives a proper displacement of the fluid present in the annulus during the cementing sequence of a P&A operation.
• a method ensuring that a sealing fluid is placed in the annulus in a safe, controlled and confirmed manner. More specifically, the inventive method provides a placement of the scaling fluid in a controlled manner, where the sealing fluid is placed in the desired /one in the well to ensure that the barrier complies with Governmental standards as well as other applicable standards (DNV. NORSOK. API etc.).
• the present invention relates to a method of performing a plug and abandonment operation or during other operations where setting of a barrier in the well is required by the use of a multitask tool, for instance a combined perforate and wash tool or just a wash tool, where the tool is used to displace both the washing liquid and the sealing liquid.
• a multitask tool for instance a combined perforate and wash tool or just a wash tool, where the tool is used to displace both the washing liquid and the sealing liquid.
• the fluid displacement arrangement comprising a plurality of radial holes.
• the lower and upper set of sealing arrangement being comprised of cups.
• cups e.g. swab cups
• the method may further comprise, subsequent to step c), but prior to step d), pulling and lowering the tool for a number of times in the perforated section for performing additional washing of the perforated section.
• the method may further comprise, after step g). a step h) comprising by-passing excess scaling fluid or present annular fluid through a bypass-system bypassing the sealed portions of the well.
• bypass-system is arranged in the tool and the sealing fluid or present annular fluid may be lead from the annulus through a second set of openings of the bypass-system, further through the tool and out of a first set of openings of the bypass-system to a location above the sealed portions of the well.
• the tool comprises an internal plugging element.
• which internal plugging element may be adapted to be activated by means of a remote operation.
• the sealing fluid may comprise cement for forming a cement plug.
• the sealing fluid may also comprise other fluids such as San dab and®. Thermaset® (Wellcem). Liquid Stone® or similar.
• the steps may be performed in a single trip in to the well. In another embodiment of the method, the steps may be performed in two or more tri ps in to the well.
• the washing fluid and the sealing fluid may be lead through a plurality of radial holes of the displacement arrangement, and the radial holes may be arranged in a spaced-apart relationship around a circumference of the tool.
• the method may further comprise the step of squeezing present annular fluid or sealing fluid from a location above the sealed portions to a location below the scaled portions in the well by leading the fluid through a first set of openings of a bypass-system above the sealed portions and out of a second set of openings of the bypass-system below the scaled portions.
• the method may further comprise, after step h), a step i) comprising lifting the tool to a position above the scaling fluid in the well and cleaning the tool by pumping a washing fluid through the tool and the first and second set of openings of the bypass-system.
• Fig.1 - 7 show a sequence of displacing fluids present in a well annulus by the filling of a sealing fluid that will make sure that any pressuri/ed formation areas are isolated and that they will not leak to surface, and
• Fig.8 shows a larger overview of the situation in Fig. 1
• Fig. 1 shows the situation after that a desired /one of the well has been perforated, washed and cleaned by a combined perforate and wash tool 1.
• a perforate gun is not used when there are existing perforations that can be employed for plugging. Otherwise the perforate gun is run with the wash tool 1 to make perforations.
• a packer or bridge plug schematically illustrated in Figure 8, is also located further down hole to support the sealing material to be delivered into the tubular that is perforated above to support the sealant below the perforated section 10. The plug can be run in on the same trip or a different trip as the tool 1.
• the combined perforate and wash tool 1 has been lowered in the well until one lower set of sealing arrangements in the form of cups 2 is arranged below the lower part of the perforated section 10. the perforated section 10 being indicated by the broken lines, and one upper set of scal ing arrangement in the form of cups 3 is just above the lower part of the perforated section 10.
• This allows for circulation of seal ing fluid (colored light grey i n the Figures ) between the lower set of seal ing arrangement 2 and the upper set of sealing arrangement 3. and out through a plural ity of radial holes 4 arranged between the lower and upper sets of scal ing arrangements 2, 3 in the tool 1 from an inside of the tubing 1 1 .
• the flow pattern is disclosed by the arrows A 1 .
• scal ing fluid e.g. cement . Thcrmasct®. Sandaband® or any other fluid, substances or other sealant or si mi lar.
• the level of sealing fluid has risen i n the wel l, to a position in which the scali ng fluid i s at a higher elevation than the tool 1 in the wel l .
• Fig. 3 the tool 1 has been pul led upwards in a control led manner while pumping of the sealing fluid has proceeded.
• the level of the sealing fluid above the tool 1 is held substantially constant.
• the sealing fluid above the perforate and wash tool 1 has begun to f i 11 the tool 1 from the annulus v ia the perforate and wash tool 1 bypass system, allowing the seal ing fluid to f i 11 the void below the perforate and wash tool 1 . ensuring solid sealing fluid across the cross sectional area of the perforated section 10.
• the bypass-system comprises a first set of openi ngs 1 2 leadi ng from the annulus towards the inside of the tool 1 . bypassing the first and second sets of seali ng arrangements 2. 3.
• the by-pass lines extending from the openings i n the fi rst set of openings 1 2 to the second set of openings 1 3. may be separate lines leading from one opening to another opening, or alternatively, one or more common lines for a plurality of openings.
• sealing fluid can be "sucked" from above the tool 1 towards the area below the tool 1 due to a change in pressure over the tool 1 , as the tool 1 is pul led towards the surface, leaving an area without seali ng fluid.
• bypass-system al lows for sealing fluid to flow through the first set of openings 1 2 through the tool 1 and out of the second set of openi ngs 1 3. providing a w hole cont i nuous seali ng fluid plug in the wel l (also shown by arrows A4, A5).
• Fig. 4 a continued pul ling of the tool 1 has taken place unti l the perforate and wash tool 1 has been pul led above the perforated section 10 in the wel l and positioned i nside a non-perforated tubular 15. Now the pumping of scal ing fluid is stopped. Now referring to Fig.5 it is disclosed a situation where the internal plugging device 7. which can be opened and closed multiple times, has been opened. This might be done in numerous ways of remote actuation, e.g. electric actuation, hydraulic actuation or by using a ball element, a valve or dart, a mud pulse, cement etc. By opening the internal plugging clement 7. the scaling fluid is allowed to be displaced through the tool 1.
• remote actuation e.g. electric actuation, hydraulic actuation or by using a ball element, a valve or dart, a mud pulse, cement etc.
• the bypass-system which is described in greater detail above, allow for the sealing fluid to be displaced through the bypass-system and up to a location above the tool 1.
• the displacement of the sealing fluid is disclosed by arrows A 6.
• A7. i.e. in through the second set of openings 13, further through the tool 1 and out of the first set of openings 12.
• the tool 1 is continued to be pulled upwards until the sealing fluid is placed in the well as desired.
• Fig.6 it is disclosed a situation where the tool 1 has been pulled above the top of the sealing fluid.
• a cleaning process of the tool 1 has been performed, e.g. by pumping washing fluid through the inside of the tubing 11 and down through the tool 1 and the open internal plugging device 7.
• washed fluids can flow into the second set of openings 13, up through the tool 1. and out of the first set of openings 12.
• the cleaning fluid is preferably another fluid than the sealing fluid, and such fluids are known to the person skilled in the art.
• Fig.7 discloses a situation where it is performed a squeeze of excess fluids in the well.
• Scaling elements 16 are arranged around the tubing 11 and the squeeze is performed by pushing the tubing 11 and tool 1 downwards into the well. Another way to do this is to be able to close ports 13 so that there is no need for the seal 16 and move the tool 1 downholc. with or without fluid moving through the tool 1.
• a fluid will be run through the tubing 11.
• the tool 1 can be pulled to the surface instead of squeezing in cases where squeezing of excess fluid is unnecessary.
• Fig.8 discloses an overview of the perforate and wash tool 1 according to the invention arranged in the well, subsequent to that first a perforating operation and thereafter a washing operation have taken place, but prior to that the sealing fluid is pumped into the well.

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• 2014
  • 2014-08-04 AU AU2014309518A patent/AU2014309518B2/en active Active
  • 2014-08-04 EP EP14755724.3A patent/EP3036395B1/de active Active
  • 2014-08-04 WO PCT/NO2014/050136 patent/WO2015026239A2/en active Application Filing
  • 2014-08-04 DK DK14755724.3T patent/DK3036395T3/da active

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