CA2017164A1 - Fluid and abrasive delivery system for hyper pressure fluids - Google Patents

Abstract

TITLE: FLUID AND ABRASIVE DELIVERY SYSTEM
FOR HYPER PRESSURE FLUIDS

INVENTORS: RODERICK D. ,cLEOD
DWIGHT LOREE

ABSTRACT
An improved method and apparatus for introducing hyper pressure fluids and abrasives into well bores for utilization in the operation of downhole tools during procedures such as reaming out of broken tools, jet perforating of casing and formation and jet drilling is presented.
Hyper pressure tubing is inserted through coil tubing to a hyper pressure nozzle at one end of the coil tubing. Abrasive material may be injected into the annulus between the coil tubing and the hyper pressure tubing for delivery to the nozzle and thence mixing with the hyper pressure fluid. The hyper pressure fluid is injected down the hyper pressure tubing.

Description

- 2 -FIELD OF INVENTION
This invention relates to an apparatus and method for use in oil and gas well servicing and drilling. -BACRGROUIID OF THE INVENTION ~:
Many of the procedures in oil and gas well ~ -drilling and servicing require the removal of high strength ferrous or rock material from the wellbore.
A high strength steel drilling bit may break off in the well and have to be removed by reaming it out with ~
an even higher strength steel or diamond reamer. The - :-rock material would be in the formation which is being drilled through and may vary between soft limestone to granite and igneous rock. There exist the tools to do this in the confines of the well, such as reamers, ~ -abrasive jet cutting tools and drills, but to date, these conventional oilfield practices in oil and gas wells are far behind the abilities of tools in general -use for surface jobs of the same type.
As a preface to the following illustrations which utilize fluid, it i8 noted that the work done by -~
any of the tools discussed is due to the power that is delivered to the tool in the working position. This power is a product of the amount of fluid delivered to the ~ool and the pressure at which it is delivered and is called the jet energy. It can be generalized that a large volume of fluid at a low pressure will have the same jet energy as a small volume of fluid at a high pressure. The large volume of fluid requires ; `
large pumps, large internal diameter tubing to route -it through and attendant abrasion of these items due to the large volume of fluid-abrasive. The small volume-hiqh pressure system has small pumps, small ~- ~
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2017~64 tubing and low wear rates due to the low volumes of fluid-abrasives.
A first illustration of oilfield practice is the procedure of reaming. Tools which are used for reaming are required to be harder than the material they will be cutting and must be run with great care by a drilling rig lest they also become stuck and broken in the wellbore. The problem of cutting out a broken reamer may be insoluble. Reaming is a time consuming procedure with many inherent risks and possibilities of failure.
A second illustration is the procedure of jet perforating. In this operation, a high pressure mixture of fluid and abrasive material is pumped down the well through a string of tubing. At the lower end of the tubing it exits through a jet nozzle and impinges on the wellbore casing, wearing it away and then cutting into the underground formation with the same jetting action. The limits imposed on this type of operation are set generally by the pressure and rate of the fluid in the tubing and the life of the jet under the action of the abrasive in the fluid. A
maximum pressure for the tubing used for this type of service is in the range of 15,000 psi and a rate of about eighty gallons per minute. The service life for a jet in this service may be in the range of twenty to thirty minutes. The velocity of the fluid~abrasive ' mixture in the tubing creates tubing wear. Jet perforating is also damaging to the pressure pumps which supply the fluid-abrasive mixture.
A third illustration is the procedure of jet drilling. This field is fairly new, and much experimenting has been done. Most of the information on these experimental drilling projects is .- .. ~

''' ' "' '' ' confidential and unavailable, but the results knownhave not been generally favourable. In jet drilling, a high pressure jet of fluid, sometimes with an added abrasive, is pumped down a tubing string to a jetting head and the jet bores its way through the formation.
Extra high pressures in special tubing strings in the range of 20,000 psi have been utilized by Gulf Oil in their experiments. The problems of pressure maximums and jet life which limit jet perforating also affect this type of drilling.
Existing methods for running hyper pressure fluids to the various downhole tools used in the oilfield operations of jet drilling, reaming and perforating rely on the well known use of multiple joints of drill pipe, with a comparable length of hyper pressure tubing inside, being threaded together and run down the well. The hyper pressure tubing has a connection at each end of the tubing, being generally a push together type of union. With the use of multiple connections, there is the problem of leakage of the hyper pressure fluid with the attendant loss of time in having to pull out the drill pipe and find and repair the leak. The overall lenqth of drill pipe and internal tubing cannot be pressure tested prior to being used in the service. An example of this type of drill pipe and internal hyper pressure tubing is seen in the FlowDril (FlowDril is a trade-mark of ! FlowDril Corporation of Kent, Washington, U.S.A.) system which has been developed by FlowDril Corporation in concert with Grace Drilling Co.
In conventional industrial surroundings, the cutting problems of reaming, jetting and jet drilling have been handled with great ease by the use of hyper pressure fluid cutting tools. Hyper pressure is the " ~ "' ~ ' ~ 5~01716 4 term applied to fluid pressures which range from 20,000 psi up to over 100,000 psi. The tools which use these pressures for cutting and drilling steel and concrete generally use filtered water as the fluid, and the amount of fluid utilized is in the range of three to four gallons per minute. An abrasive, when used, is added in the tool head after the jet and does not cause wear to the hyper pressure tubing or the jetting nozzle. The distance from the hyper pressure supply pump to the tool is usually a few hundred feet, while the abrasive may be added from a supply much closer at hand. In the trade, these are called water knives (without an abrasive) and abrasive jets with abrasives. There are a multitude of these tools on - `
the market, and the art of jet design is far advanced.
As an example, jets have a life measured in the hundred hours as opposed to minutes with the existing oilfield designs. To date these tools have not been available for operation in such surroundings as found ~
in an oil or gas well, henceforth called a well, due -to the impossibility of supplying the hyper pressure fluid and abrasive to the tool separately over a several thousand foot distance down the well.

8m ~ARY OF THD INVENTION :
: ~` '' The invention comprises a method for supplyi;ng a hyper pressure fluid and an abrasive, in ~ ~
separate supply passages, to a conventional tool head ~-in the confines and depth of a well through continuous flexible external and internal tubings. The complete system can be tested for possible pressure leakage before being utilized in the required service. In one aspect, the invention comprises an improvement to the '; ~ `: ~ : ~;

20171~4 . ,:;, existing method of supplying a mixture of pressurized fluid and abrasive material to a jetting or drilling head in the confines and depth of a well.
The invention comprises an endless flexible hyper pressure inner tube housed in an endless flexible steel outer tube. The hypar pressure fluid is pumped down the hyper pressure tube to the tool head in the well, this tool head being constrained in place by the flexible steel outer tube.
The abrasive in a slurry form is pumped down the annulus formed by the flexible steel outer tube and the hyper pressure inner tube and into the conventional jetting tool for combination with the hyper pressure fluid after this fluid has passed through the jet. Various cutting and drilling actions will be done by the different commercially available tools.
With the aid of the hyper pressure fluid and abrasive mixture, such operations as cutting off tubing, reaming out foreign objects, perforating the formation and jet drilling in either the vertical or horizontal direction may be done with conventional tools and guidance systems with the increased dependability created by having no untested connections in the flow passages for the hyper pressure fluid and the abrasive additives.
Thus in one aspect, the apparatus of the ` invention provides a drilling apparatus comprising:
coil tubing injector; coil tubing stored on the coil tubing injector, the coil tubing having a top end and a bottom end; hyper pressure tubing sheathed within the coil tubing and extending from the top end to the bottom end; means in fluid connection with the hyper pressure tubing at the top end of the coil tubing for injecting hyper pressure fluid into the hyper pressure tubing; and a hyper pressure head in fluid connection with the hyper pressure tubing and located at the bottom end of the coil tubing.
In another aspect, the apparatus of the invention provides the drilling apparatus as further including means in f luid connection with the coil tubing at the top end of the coil tubing for injecting a fluid into the annulus and the hyper pressure head having means for mixing the fluid and the hyper pressure fluid.
In another aspect, the method of the invention provides a method of drilling a well using a hyper pressure head connected to a length of hyper pressure tubing, the method comprising: connecting the hyper pressure head to a length of coil tubing, the hyper pressure tubing being sheathed within the coil tubing; running the hyper pressure head into the well at the end of the coil tubing; and supplying the hyper pressure head with hyper pressure fluid.
In another aspect, the method of the invention includ~s the coil tubing and the hyper pressure tubing defining an annulus and further ~comprising supplying the hyper pressure head with abrasive fluid through the annulus.
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~RI~F DE~CRIPTION OF THE FIGURE~

There will now be described preferred : : .
embodiments of the invention, by way of example, with -~
reference to the drawings in which like numerals : :~
denote like elements and in which: -~ :
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Figure 1 shows a method of reeling concentric tubing according to the invention onto a conventional endless tubing unit;
Figure 2 shows a side view cross section of the concentric tubings attached to a supply of hyper pressure fluid and a supply of fluidized abrasive;
Figure 3 shows a side view cross section of the concentric tubings attached to one embodiment of a hyper pressure head;
Figure 4 shows a side view cross section of the concentric tubings attached to another embodiment of a hyper pressure head;
Figure 5 show an end view of the hyper pressure head shown in Figure 4;
Figure 6 shows a side view cross section of the concentric tubings attached to a still further embodiment of a hyper pressure head; and Figure 7 show an end view of the hyper pressure head shown in Figure 6.
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DBTAIL~D D~8CRIPTION O~ TH~ PR~FERR~D gMBODIMgNT8 In this patent, the following definitions are used. Sheathed means that the hyper pressure tubing 220 is encased within the coil tubing 110 so that the weight of the hyper pressure tubing 220 is at - least partially born by the coil tubing 110, at least to the extent that the weight of the hyper pressure tubing 220 does not exceed its strength. As described below, it is desirable that there remains sufficient spaae around the hyper pressure tubing 220 so that fluid may be circulated within the annulus between the hyper pressure tubing and the coil tubing.
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g Hyper pressure means at pressures above about 20,000 psi.
Hyper pressure head means a tool for use in downhole operations such as reaming, perforating, cutting, jet drilling and jet assisted drilling and that carries out the actual cutting actions involved in these operations by generating one or more jets formed by a hyper pressure fluid.
Abrasive fluid means a fluid containing abrasive material such as sand.
Hyper pressure fluid means a fluid that is pressured so that it reaches hyper pressure at the hyper pressure head.
Referring to Figure 1, there is shown a conventional coil tubing injector 114 mounted on a platform 130 with conventional trailer wheels 132 and spool mount 134. Mounted on the spool mount 132 is a storage reel (details not shown) with coil tubing 110 wound onto the storage reel in conventional fashion.
The coil tubing injector 114 may be of any design such as is well known in the art and need not be described further here. The coil tubing is also well known in the art and may be obtained from Quality Tubing Inc.
of Houston, Texas. It should preferably have a pressure rating of at least 8000 psi, but in some applications could be lower, depending on the depth of well.
The coil tubing 110 passes through tube straightening means and drive head 128, also well known in the art, into a well 136 through conventional well head 138. The coil tubing 110 then passes down the well 136 within the casing 140, to a nozzle or jet cutting tool 3, described in more detail below in relation to Figure 3.
'~'` ', ''' . ".-' ', 20171~i The upper end of the coil tubing 110 has a coupling or rotary joint 2 for the supply of fluid into the coil tubing 110. The rotary joint 2 is fed by the line 116 from the hyper pressure intensifier pump 120, which pumps the hyper pressure fluid 124, and by the line 118, from the plunger pump 122, which pumps the blend of fluid abrasive 126. The line 116, rotary joint 2 and hyper pressure pump 124 together constitute means in fluid connection with the hyper pressure tubing at the top end of the coil tubing for injecting hyper pressure fluid into the hyper pressure tubing. The rotary joint 2 is conventional except as described below in relation to Figure 2. The line 118, the rotary joint 2 and plunger pump 122 together constitute means in fluid connection with the coil tubing at the top end of the coil tubing for injecting a fluid into the annulus.
The hyper pressure intensifier pump 120 may be for example a UHP intensifier pump from Flow Systems Inc., of Kent, Washington, and the plunger pump 122 may be for example USS Oilwell A-324 triplex plunger pump from USS Oilwell, Dallas, Texas.
The coil tubing 110 houses continuous hyper pressure tubing 220 which runs concentrically along the entire length of the coil tubing 110 from the rotary joint 2 to the jet cutting tool or hyper pressure head 3. The hyper pressure tubing 220 is sheathed within the coil ~' tubing 110. The hyper pressure tubing 220 may be inserted in the coil tubing 110 by any of various ways such as running a line through the coil tubing 110 and pulling the hyper pressure tubing 220 after it (as is known in the art for running tools into the well) or suspending the coil tubing 110 down an abandoned well .

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and dropping the hyper pressure tubing 220 down inside the coil tubing 120.
Referring to Figure 2, there is shown a rotary joint 2 in considerable detail. A conventional rotary joint 210 with seals 212 is provided to connect the stationary hyper pressure line 116 to the rotating hyper pressure line 230. The rotary joint 210 and seals 214 may be for example a rotary swivel joint available from Weco-Chiksan, FMC Corp. United States.
The hyper pressure tubing 230 is connected to the hyper pressure tubing 220 by a steel to steel threaded joint 218 such as a Sno-Trik (tm) steel to steel cone fitting available from Swagelock. The hyper pressure tubing may be for example a UHP hose assembly available from Flow Systems Inc.
Abrasive fluid mix 126 is pumped into the annulus 216 between the coil tubing 110 and the hyper pressure tubing 220 through the rotary swivel joint 214, and thence down the well as illustrated in Figure 1. The rotary swivel joint 214 is of similar construction to the rotary joint 210 except that it include an annulus and the coil tubing 110 includes a pair of openings diametrically spaced so that the abrasive fluid mix can enter the annulus 216.
Referring to Figure 3, there is shown a detail of the hyper pressure head 3 shown schematically in Figure 1. The hyper pressure head 3 includes an ' ~ indexing cutting head 334 connècted by threads to the bottom end of the endless coil tubing 110 and also , . . . ..
connected by threads to the bottom end of the hyper pressure tubing 220, with appropriate seals 330 (such as polypropylene glass filled seal rings). A venturi chamber 336 is provided for the mixing of the fluid abrasive 126 and the hyper pressure fluid 124. The ~'' '., ':

2iO171~64 abrasive enters the venturi chamber 336 from the annulus 216 through flow passages 338. The hyper pressure fluid 124 enters the venturi chamber 336 from the hyper pressure tubing 220 through a passage 340.
If desired, the hyper pressure fluid may be used for drilling without the use of the abrasive fluid mix.
The hyper pressure head 3 is preferably Model V1-061-C5 cutting head available from Vector Engineering Ltd.
of Edmonton, Canada.
Referring to Figures 4 and 5, an alternative hyper pressure head 410 is shown attached to the bottom end of the coil tubing 110 and the bottom end of the hyper pressure tubing 220. Hyper pressure fluid 124 and abrasive fluid mix 126 may be supplied to the hyper pressure head 410 through passageways 416 and 418 respectively to mixing chamber 420 for delivery to the jets 414 disposed circumferentially about the lower end of the hyper pressure head 410. The jets 414 may be arranged in any of many configurations depending on the application. In this embodiment, the hyper pressure head 410 may be used to remove obstructions from the well such as lodged material 412 using the mix 332 of abrasive fluid 126 and hyper pressure fluid 124, or just the hyper pressure fluid 124 alone . Hyper pressure head 410 may be for example model no. V1-066-C5 available from Vector Engineering Ltd. of Edmonton, Canada.
Another embodiment of a hyper pressure head 610 is shown in Figures 6 and 7. The hyper pressure head 610 includes jets 612 fed through passageways 618 by hyper pressure fluid 124, while the fluid 126, pumped down the annulus between the coil tubing 110 and the hyper pressure tubing 220, is used to flush the cuttings from the formation 616, out of .

20~716~

the well bore. Figure 7 shows one of the many jet drilling head configurations that may be uised. The hyper pressure head 610 may be for example model no.
V3-006-D5 available from Vector Engineering Ltd. of Edmonton, Canada.
::-OPERATION OF PRE~B~EL~Qm ~ENTS
The method of the invention uses a hyper pressure head such as is shown in Figures 3, 4 and 6, the hyper pressure head being connected to a length of hyper pressure tubing, and includes the following steps: connecting the hyper pressure head to a length of coil tubing, the hyper pressure tubing being previously sheathed within the coil tubing (or alternatively including the step of sheathing the hyper pressure tubing within the coil tubing; running the hyper pressure head into the well with the hyper pressure head at the end of the coil tubing; and supplying the hyper pressure head with hyper pressure fluid.
The steps may also include supplying the hyper pressure head with abrasive fluid through the annulus defined by the hyper pressure tubing and the coil - tubing.
Referring to Figure 1, hyper pressure fluid is pumped into the flexible hyper pressure tubing inside the coil tubing 110 by the hyper pressure pump 120. At the same time, the fluid-abrasive mix 126 is pumped by the fluid-abrasive pump 122 through the annulus in the coil tubing 110. At the hyper pressure head, the two streams of fluid are combined in conventional manner and the casing may be cut in a vertical manner by moving the hyper pressure head up or down in the well by the action of the tubing drive head 128.

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The several different jet cutting and drilling headæ which utilize hyper pressure fluid all operate in the same general way and are available in a variety of shapes and sizes, with various standard attachments for rotating and direction changing such as would be found in directional drilling.
As shown particularly in Figures 6 and 7, ~
the annulus may be used to supply circulating fluid to ~ -the cutting area or not used to circulate fluid at -all, and the hyper pressure fluid alone used for -drilling. ~;
It will be understood that immaterial modifications may be made by persons skilled in the art to the invention as defined by the claims that follow without departing from the essence of the `
invention.

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Claims (9)

WE CLAIM:

1. A drilling apparatus comprising:
a coil tubing injector;
coil tubing stored on the coil tubing injector, the coil tubing having a top end and a bottom end;
hyper pressure tubing sheathed within the coil tubing and extending from the top end to the bottom end;
means in fluid connection with the hyper pressure tubing at the top end of the coil tubing for injecting hyper pressure fluid into the hyper pressure tubing; and a hyper pressure head in fluid connection with the hyper pressure tubing and located at the bottom end of the coil tubing.

2. The drilling apparatus of claim 1 in which the coil tubing and the hyper pressure tubing form an annulus between them and further comprising:
means in fluid connection with the coil tubing at the top end of the coil tubing for injecting a fluid into the annulus; and the hyper pressure head having means for mixing the fluid and the hyper pressure fluid.

3. The drilling apparatus of claim 2 in which the fluid is an abrasive fluid.

4. The drilling apparatus of claim 1 in which the hyper pressure head includes a single curved jet.

5. The drilling apparatus of claim 1 in which the hyper pressure head includes a lower end and a plurality of jets disposed circumferentially about the lower end.

6. A method of drilling a well using a hyper pressure head connected to a length of hyper pressure tubing, the method comprising:
connecting the hyper pressure head to a length of coil tubing, the hyper pressure tubing being sheathed within the coil tubing;
running the hyper pressure head into the well with the hyper pressure head at the end of the coil tubing; and supplying the hyper pressure head with hyper pressure fluid.

7. The method of claim 6 in which the coil tubing and the hyper pressure tubing define an annulus and further comprising:
supplying the hyper pressure head with abrasive fluid through the annulus.

8. A method of drilling a well using a hyper pressure head connected to a length of hyper pressure tubing, the method comprising:
sheathing the hyper pressure tubing within a length of coil tubing;
connecting the hyper pressure head to the length of coil tubing;
running the hyper pressure head into the well with the hyper pressure head at the end of the coil tubing; and supplying the hyper pressure head with hyper pressure fluid.

9. The method of claim 8 in which the coil tubing and the hyper pressure tubing define an annulus and further comprising:
supplying the hyper pressure head with abrasive fluid through the annulus.