Background of the Invention
The disclosed invention is an improvement over inventors' prior invention U.S. Pat. No. 3,934,469, issued Jan. 27, 1976.
As an aid to improving steam flood efficiency in secondary recovery in old oil or depleted wells for example, it is greatly beneficial to know the steam quality at any particular location in the well or sandface of a steam injection well. It would be desirable to collect and trap a representative sample of the steam liquid phase or water droplets flowing to the surface and retrieve this sample for analyzing while the steam vapor phase or vapor passes on through. The sample could then be checked for either total dissolved solids or chloride content and compared to the steam generator feedwater total dissolved solids or chlorides. Hence, the quality may be determined from a ratio of the total dissolved solids or chlorides of the steam entering the wellhead to the total dissolved solids or chlorides in the steam water droplets from the sampler at any desired location in the well, as at the bottom of the well, if so desired.
Objects of the Invention
Accordingly, a primary object of this invention is to provide at least one method for collecting a sample of the steam water droplets at any location or depth in a well to determine the quality of the steam that has arrived at the bottom for injection purposes, for example, compared to the quality of the steam prior to entry into the well.
Another primary object of this invention is to provide at least one method for forming a sampler for sampling steam water droplets at any location in a well.
A further object of this invention is to provide a method for sampling steam at any depth in a well, a method for forming a sampler for sampling steam at any depth in a well, and at least one steam sampler, each of which is easy to operate, is of simple configuration, is economical to build and assemble, and is of greater efficiency for sampling steam at the bottom of a well just prior to penetrating the surface of a petroliferous strata of an oil well, for example.
Other objects and various advantages of the disclosed methods and steam sampler will be apparent from the following detailed description, together with the accompanying drawings, submitted for purposes of illustration only and not intended to define the scope of the invention, reference being had for that purpose to the subjoined claims.
Brief Description of the Drawings
The drawings diagrammatically illustrate by way of example, not by way of limitation, one form or mechanism for carrying out one method of the invention and for being formed by the other method of the invention wherein like reference numerals have been employed to indicate similar parts in the several views in which:
FIG. 1 is a schematic elevational view of the sampler while hanging from a wireline in the upper portion of a well;
FIG. 2A is a schematic longitudinal section view of the upper portion of one embodiment of the sampler, per se;
FIG. 2B is a schematic longitudinal sectional view of the lower portion of the sampler of FIG. 2A; and
FIG. 3 is a sectional view taken at 3--3 of FIG. 2B.
The invention disclosed herein, the scope of which being defined in the appended claims, is not limited in its application to the details of construction and arrangement of parts shown and described for carrying out or made by the disclosed methods, since the invention is capable of other embodiments for carrying out other methods and of being practiced or carried out in various other ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Further, many modifications and variations of the invention as hereinbefore set forth will occur to those skilled in the art. Therefore, all such modifications and variations which are within the spirit and scope of the invention herein are included and only such limitations should be imposed as are indicated in the appended claims.
Three inventions are described hereinafter, a new method for collecting a sample of the steam water droplets, a new method for forming a sampler, and a new steam sampler.
Description of the Methods
This invention comprises a method for sampling steam at any location from the bottom to the top of a well for determining the quality of the steam just prior to injecting into the formation, and a method for forming a steam sampler.
Method for Sampling Steam
A typical method of the invention for collecting a liquid water droplet sample of steam at any depth or position in a well having a pressure chamber at the top to determine the quality of the steam that has arrived at the bottom for injection into the petroliferous strata formation relative to the steam quality input at the surface comprises the method steps of,
(1) passing the steam that has arrived at the desired location in the well through slots into the upper end of a cylindrical vessel,
(2) passing the steam from the slotted upper end of the cylindrical vessel down into an annulus formed between the lower end of the cylindrical vessel and a tube means fixed longitudinally internally of the cylindrical vessel,
(3) passing the steam vapor portion that has entered the annulus back out of the annulus through holes in the tube means,
(4) passing the steam vapor from the holes in the tube means out of the lower end of the cylindrical vessel,
(5) passing the steam water droplets through perforated baffles into the annulus so that spillage and slushing out are prevented when vapor flashing of the water occurs as the pressure is bled off for recovery of the steam water,
(6) collecting the steam water droplets in the annulus until the liquid level reaches the lowest opening in the tube means for collecting a predetermined amount of water, as about 190 cc, in the disclosed embodiments of the annulus, and
(7) raising the sampler having the sample of steam water droplets therein up into the pressure chamber for recovery at the surface.
More briefly stated the method for collecting a steam sample at any particular location of depth in a well comprises,
(1) passing the steam that has arrived at the desired depth of the sampler in the well into an annulus formed between the tube means and the cylindrical vessel,
(2) passing the steam vapor into the tube means through openings therein and out the lower end of the tube means, and
(3) collecting the steam water droplets in a perforated baffled enclosed annulus, for recovery at the surface.
Method for Forming a Steam Sampler
A method for forming a sampler for collecting a liquid phase or water droplets sample of steam at any desired depth or location in a well to determine the quality of the steam that has arrived at that depth for injection into the petroliferous strata formation relative to the steam quality input at the surface comprises the method steps of,
(1) forming an elongated cylinder having closed upper and lower ends with a diameter substantially less than that of the well to be sampled,
(2) attaching a coupling means on the cylinder upper end for connecting support means thereto for lowering the cylinder to any desired position in the well, such as but not limited to adjacent the well bottom,
(3) forming slots in the cylinder upper end for receiving steam,
(4) fixedly mounting an open ended elongated tube in the lower end of the cylinder with the tube extending upwardly from its bottom open end to a position below the slots for forming an annulus between the tube and the cylinder for receiving the steam from the slots,
(5) perforating the upper end of the tube so that the steam vapor passes into the tube through the perforations therein for exhausting from the cylinder bottom as the steam water droplets collect in the annulus up to the perforations,
(6) closing the top of the elongated tube with a cap having legs extending below the perforations for guiding the steam into the annulus, and
(7) mounting a suitable number of perforated baffles on the cap legs for preventing spillage and slushing of the hot steam water due to vapor flashing of the water droplets when the pressure is bled off for recovery of the steam water droplets for testing.
A Steam Sampler
While various samplers may be made by the above method, the following is one examplary steam sampler of several which may be manufactured.
FIG. 1 illustrates schematically an injection well 10 for example having casing 11 in which steam is generated on the surface and injected through injection line 12 under high pressure through valves 13 and 14 into the well to emerge at the bottom for penetrating the adjacent petroliferous formation for displacing the oil therein toward production wells nearby.
FIG. 1 illustrates the new steam quality sampler or cylindrical vessel means 16 suspended in a conventional lubricator or pressure chamber 17 removeably mounted with detachable knock-off connection 18 on top of the housing of a third high pressure valve 15. The steam quality sampler is suspended on cable or wireline 19 over first pulley 20 supported by a conventional boom 21. The line 19 continues by second pulley 22 to a wireline unit 23 for reeling in or paying out the line 19 for positioning the steam quality sampler where desired anywhere from in top of the pressure chamber 17 down to the bottom of the well 10.
Steam injection line 12 also has passage 24 with valve 25 for diverting the steam from the well to a vent or another well (neither shown), as well as a pressure gauge 26. Pressure chamber 17 has a bleed valve 27.
FIG. 2A illustrates in section the upper portion of the sampler 16 and FIG. 2B illustrates in section the lower portion of the sampler.
FIG. 2A is a longitudinal sectional view illustrating details of the upper portion of the new steam quality sampler 16 made by the previously disclosed method. A sucker rod coupling 28 forms the top portion to which is connected the wireline 19 for supporting the steam quality sampler where desired in the well. Under the sucker rod coupling 28 is welded a slotted upper portion 29 having slots 30 around the periphery thereof. A connecting sleeve 31 is welded between the slotted upper portion 29 and an upper cylindrical vessel member 32 for forming an interconnecting passage therebetween.
FIG. 2B discloses the lower sampler portion, wherein a lower cylindrical vessel member 33 has an upper threaded end 33a screwed onto a lower threaded end 32a of the upper cylindrical vessel member 32. A bottom ring or vessel lower outlet 34 is welded to the bottom of the lower cylindrical vessel portion. An open ended elongated water vapor separation tube 35 is welded to the vessel lower outlet 34 and extends internally of the vessel up to a position just under the slots 30 for forming an annulus 36 between the tube 35 and the upper and lower cylindrical vessel members 32-33. While the above described fixed connections are described as being weld joints, any other suitable type or equivalent connections may be utilized. Likewise while a threaded joint 32a-33a is preferred between the two upper and lower cylindrical vessel members 32, 33, other suitable detachable joints may be used, if desired.
This water vapor separating tube 35, FIG. 2B, is a principal element in combination with the cylindrical vessel for forming the steam quality sampler. A plurality of holes 37 are formed in the upper end of the water vapor separation tube with the lower holes determining the particular volume of the annulus desired, as 190 cc for example, in the lower cylindrical vessel member 33 for catching and retaining the steam water droplets. A cap 38 screws on top of the water droplets separation tube 35 for closing the upper opening. Cap 38 has three legs 39 extending down below the lowest holes 37 for supporting a suitable number, such as but not limited to, two perforated baffles, 40 and 42, screwed thereon. The baffles 40, 42 each has a plurality of holes 41 and 43, respectively, for permitting the steam water droplets to pass therethrough while the steam vapor passes from the annulus through the holes 37 into the water-vapor separation tube.
Briefly in operation the steam quality sampler 16, FIG. 1 is lowered through open valves 14 and 15 into the well 10 from inside the pressure chamber 17 by paying out the line 19 from the wireline unit 23 to the desired depth. With valve 25 in the diversion passage 24 closed and valve 13 open, a predetermined amount of steam is injected into the well for passing through the steam quality sampler positioned at the particular depth in the well in the petroliferous strata where the quality of steam is desired. After passing through the slots 30, FIG. 2a, the steam passes down through connecting sleeve 31, down through the upper cylindrical vessel member 32, and down into the annulus 36, FIG. 2b. Here, the steam vapor passes into the water-vapor separation tube 35 through its holes 37, down the tube, and out the vessel lower outlet 34. However, the steam water droplets continue straight down the annulus 36 and through the perforated baffles to the bottom of the annulus.
After the annulus has filled up to the lower row of holes therein of steam water droplets as calculated by the amount of time of steam injection into the well, the steam is cut off or by-passed to passage 24, FIG. 1, to other wells or vented and the steam quality sampler raised to the surface and finally into the pressure chamber 17 where valve 15 is closed and the bleed valve 27 opened slowly. After the pressure is bled off, the pressure chamber is detached from the well, the steam quality sampler removed, and the quality of the steam determined from the remaining liquid. A certain amount of water will boil off until the pressure in the sampler is down to atmospheric pressure and the temperature is below 212.degree. F. (100.degree. C.). Then the lower cylindrical vessel member 33, FIG. 2b, is unscrewed from the upper cylindrical vessel member 32 and the sample recovered.
The sample may then be checked for either total dissolved solids or chloride content and compared with the steam generator feed water total dissolved solids or chlorides to determine the quality of the steam or ratio of the total dissolved solids or chlorides in the water droplets at the well bottom or point of injection to the total dissolved solids or chlorides in the feed water at the surface. Conductivity meters provide an easy and simple system for analyzing for total dissolved solids.
The quality "Q" of the steam of a typical sample may be determined as follows (ppm-parts per million): ##EQU1## Total Dissolved Solids (TDS) at generator = 8,000 ppm Bottomhole TDC = 23,000 ppm
Full Sample = 190 cc
Remaining Sample = 120 cc (70 cc were lost due to flashing to vapor at atmospheric pressure). The TDS was concentrated in proportion to the quantity of water lost. ##EQU2##
Preferably the higher the quality of the steam at the point of injecton into the earth, the greater the penetration and the greater the production of oil from the production wells.
Accordingly, the three inventions comprising a new method for collecting steam samples from any location in a well, a new method for forming a steam quality sampler, and a new steam quality sampler for taking steam samples at any depth in a well have been disclosed above.
Obviously other samplers and other methods may be utilized for collecting steam samples and for forming a steam sampler like the embodiment of FIG. 2 than those listed above, depending on the particular information and water droplets or condensate desired.
Accordingly, it will be seen that at least one method for collecting a steam sample at any location in a well, at least one method for forming a steam sampler, and at least one embodiment of a steam sampler have been described which will operate in a manner which meets each of the objects set forth hereinbefore.
While only two methods of the invention and one mechanism have been disclosed, it will be evident that various other methods and modifications are possible in the arrangements and construction of the disclosed methods and steam collecting sampler without departing from the scope of the invention and it is accordingly desired to comprehend within the purview of this invention such methods and modifications as may be considered to fall within the scope of the appended claims.