JPS6274056A - Steel for perforating gun - Google Patents

Abstract

PURPOSE:To improve perforability by adding trace amounts of Se and Al to a steel having a specific composition containing Mn, Ni, Cr, Mo, W, etc. CONSTITUTION:The steel has a composition which consists of, by weight, 0.20-0.50% C, 0.05-0.75% Si, 0.30-1.80% Mn, >0.50-2.00% Ni, 0.50-1.50% Cr, Mo and/or W in an amount satisfying Mo+1/2W=0.10-0.50%, 0.001-0.100% Se, 0.005-0.100% Al and the balance Fe with inevitable impurities and in which amounts of P and S as impurities are regulated to <=0.025% and <=0.015%, respectively. If necessary, <=0.50% Cu or further proper amounts of V, Nb, Ti and B are added to the above composition. owing to this composition, steel for perforating gun having excellent perforability can be obtained at a low cost and stability as well as smoothness in oil and natural gas drilling operations can be improved.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides perforating with excellent perforation properties, which is used in perforating work, which is a process of oil extraction and natural gas extraction. - Concerning steel for guns.

<Prior art and its problems> Generally, when extracting oil or natural gas, as shown in Figure 1, a casing 1 is laid over the excavated oil or gas 1↑, and this is cemented (fixed with cement). After that, a large number of holes are drilled in the casing 1 and the cement layer 3 located in the oil layer 2 and gas layer in order to allow the gas to flow into the house from the oil layer 2 and the gas layer. [I3, The thing indicated by the symbol 4-(- in Fig. 1) is an excavation tower.

In addition, the drilling work, called perforating work, is an important process that cannot be omitted in oil and natural gas extraction work, and previously it was performed as shown in Figure 2. As shown in Figure 3, a plurality of perforators 8 in which a cartridge 5 is filled with gunpowder 6 and sealed with a conical copper rhino 7 is called a "perforating gun" (Vyaria gun). After screwing into the steel cylindrical body 9 (also referred to as gun duping), this barf A-rated gun 9 is suspended in the casing 1 as shown in Figure 4 to ignite the par 7 fort. The method used was to drill a hole using the resulting jet.

Note that in FIG. 4, reference numeral 10 indicates a jet stream.

The bar 74 rating gun 9 used here was of a type that could be pulled up to the ground after the work was completed, a new perforator installed, and reused.

However, in this conventional type perforating gun, the perforator 8 is installed with the perforator 8 exposed on the outside surface, so the perforator is likely to misfire or ignite accidentally due to humidity or high temperatures deep in the well, and is not necessarily smooth and reliable. The problem was that it was not possible to ensure proper perforating work.

Therefore, in recent years, in order to solve the above problem, a scallop (indentation) 11 is made on the outer surface as shown in FIG. A new type of part noting gun has been developed for drilling holes in the scalloped parts of the casing and the cement 1 layer, and perforation work using this gun has shown signs of increasing rapidly. This new type of perforating gun was disposable and was often dumped at the bottom of the well.

Note that FIG. 5(a) is a longitudinal cross-sectional view of the main part of the perforating gun, and FIG. 5(b) is a cross-sectional view of the main part.

However, this new type of perforating
Gun (41) As mentioned above, since the perforating gun itself is perforated during use,
Perforation performance has attracted attention as a major problem.In other words, when a perforator is used to make six large holes, cracks may occur in areas other than the Zuki V-lop part, rupture, or breakage. For example, the perforating gun gets caught on the inner surface of the casing, making it impossible to pull the perforating gun out of the well or dump it to the bottom of the well.

Here, the perforation property of the perforating gun component material refers not only to the property of not causing rupture or cracking when performing perforating work using a perforator, but also the property of not causing rupture or cracking around the hole. This term is used to include the ``characteristic of ensuring a clean perforation'' without the burr protruding outward.

Therefore, at present, chromium-molybdenum steels such as Al5I4140PA and nickel-chromium-molybdenum steels such as Δl5I4340 steel are used as steels for the new type of perforating guns.
Even with 'J, during perforating work,
Occasionally, it was inevitable that problems such as the above-mentioned "cracks" and "ruptures" due to insufficient perforation would occur.

<Means for Solving the Problems> The name of the present invention is intended to criticize the current situation as described above, and to use a perforating gun during perforating work carried out in the extraction of oil, natural gas, etc. From the perspective that cracks and ruptures are most attributable to the material of the perforating gun itself, as well as the design of the scallop, we have developed a steel for perforating guns that has even better perforation control properties. As a result of various researches to provide the following, we found that Se could be added to steel with a specific composition? ! It was discovered that the perforation properties of the steel were significantly improved by adding 10% of the perforation property, and that a bar 74 rating gun steel with extremely excellent perforation properties could be obtained.

This invention was made based on the above knowledge, and perforating gun steel was made with C: 0.20 to 0.50% (hereinafter referred to as % indicating the component ratio).
3i: 0.05-0.75%.

jvln: 0.30-1.80%.

Ni: More than 0.50 to 200%.

Cr: 0.50-1.50%.

One or more types of Mo or W back: Mo+1/2W 0.10-0.50%.

3 e: 0.001 to 0.100%.

Δi: 0.005 to 0.100%.

In addition to containing Cu: 0.50% or less, V': 0.01-0.10%.

Nb: 0.005-0.100%.

Ti: 0.005-0.100%.

B: Contains at least one weight of 0.0003 to 0.0050%, and consists of the remainder of Fe and unavoidable impurities, and P and S in the impurities are each P: 0.025% or less.

3: By having a composition of 0.015% or less, it not only has the necessary properties as a steel for perforating guns, but also has significantly improved perforation properties.1j It is a sign.

Next, the reason for limiting the chemical composition range to the 'fl value as described above in the steel for burno-rolling guns of the present invention will be explained.

(a) C C is an effective ingredient for improving the strength of steel, but
If the content is less than 0.20%, it will be necessary to add a large amount of alloying elements to ensure the strength required for the barf olefin ink gun.
If 01j is avoided in excess of 0%, the perforation properties will deteriorate.
It was determined that

(b) Si $1 is a necessary component for the production of 112 acids in steel, but if its content is less than 0.05%, it cannot have a sufficient deoxidizing effect; If the content exceeds 13, it may cause deterioration of perforation properties (13).
The 3i content was determined to be more than 0.0 to 0.75%.

(c) Mo Mn is an effective component for improving the hardenability, strength, toughness, and hot workability of steel, but its content (■) is 030
If it is less than 1.80%, the above characteristics improvement effect will be small;
If it is contained in excess of
The Mn content was determined to be 0.30 to 1.80%.

(d) Ni Ni is an effective component for improving the toughness and perforation properties of steel, but if its content is less than 0.50%, it will not be able to exhibit the properties improvement effect, especially the toughness improvement effect. Even if the content exceeds 2.00%, no further progress is seen in the above-mentioned property improvement effect, and the increase in the amount of Ni, which is an expensive element, also causes economic disadvantage. It was set at more than 0.50 to 2.00%.

(e) Cr0r is an effective component for improving corrosion resistance as well as strength and toughness, but if its content is less than 0.50%, the desired effect of improving the above properties cannot be obtained; Since Cr content exceeding 150% adversely affects workability, the Cr content was set at 0.50 to 1.50%.

(f) Mo and W Mo acid component and W component both have so-called hardenability, strength,
It has the effect of improving eJ properties and corrosion resistance [
, either or both of these are added, but if the content is less than 0.10% at the value of (Mo+1/2W), the desired effect on the action of 1r is achieved. is not obtained. On the other hand, since Mo and W are both expensive alloy logs, their upper limit was set (Mo4-17
・'2W] was set at 0450%. In addition, regarding the content of Mo and W (''♀), f becomes (Mo + 1 /2W)
ar assumption t 6 (7) C. This is because W has about twice the atomic strength of Mo, and is about half of Mo in terms of the above-mentioned effects.

(a) 5c SC is an extremely important component in the present invention, and has the effect of significantly improving the perforation properties of steel, and is also effective in improving the workability of the 170-hole steel III'i. However, if the content is less than 0.001%, the desired effect will not be achieved.
Even if the content exceeds 0.100%, the effect will be saturated,
The SO content was determined to be 0.001 to 0.100% because not only no further improvement in perforation properties could be obtained, but also the hot workability would be impaired.

(h) Affi Δt is an effective component for stabilizing the deoxidation of steel, homogenizing the material, and refining the grains, but if its content Φ is 0.00
If it is less than 5%, the desired effect cannot be obtained; on the other hand, o, ioo
Even if the content exceeds %, the effect will be saturated. Furthermore, increasing the At content also causes the disadvantage that inclusions in the steel increase and make the steel brittle. Therefore, the suspension including A2 is 0
．． 005~o, ioo%.

(i) Cu The Cu component has the effect of improving the perforation properties and corrosion resistance of steel, so it is an element added as necessary, but if its content exceeds 0.50%, hot workability will be affected. Cu-containing 1[
It has been set as 0.50% or less.

(j) V, Nb, Ti, and B These components all have the effect of improving the strength of steel, so it is preferable to add one or more of them. Below, the reasons for limiting the content of each component will be explained in detail, including other incidental effects.

(I) V ■ has the effect of increasing the hardenability of steel, making the crystal grains finer and increasing its strength and toughness, but its content is 0.01
If the amount is less than 0%, the desired effect cannot be obtained;
Since M content exceeding 10% causes deterioration of toughness, the content of M is set at 0.01 to 0.10%.

-(II) Nb Nb has the effect of making the crystal grains finer and improving the strength and toughness of steel, but if its content is less than o, oos%, the desired effect cannot be obtained, On the other hand, 0.100
If the Nb content exceeds 0.005%, the toughness may deteriorate, so the Nb content was set at 0.005% to 0.005%.

(I[[) Ti Ti has the effect of improving the strength and corrosion resistance of steel, but if its content is less than 0.005%, the desired effect will be reduced by 1!7, while 0 If the content exceeds 400%, it will cause toughness deterioration.
The Ti-containing peak was determined to be o, oos ~ 0.100%.

(IV) B B has the effect of increasing the strength of steel by improving hardenability, but if its content is less than 0.0003%, the desired effect cannot be obtained; %
Since B content in excess of 20% causes deterioration of toughness, the B content was set at 0.0003% to 0.0050%.

(k) P and S In order to make the steel structure homogeneous, improve perforation properties, and ensure good hot workability, the content of P and S, which are impurities, should be reduced as much as possible. However, considering the balance with the manufacturing cost of steel, the upper limits of P and S contents are set to 0.025% and 0.015%, respectively.
It was determined that

Steel having the above-described composition is melted in a converter or electric furnace, and after continuous casting or ingot formation, it is bloomed and then processed into seamless steel pipes by hot rolling; Subsequently, the material is subjected to further processing such as cold drawing to reduce dimensional tolerances, and is formed into a parts orienting gun through processes such as heat treatment of quenching and tempering, straightening processing, scallop processing, and stress relief annealing.

Next, the present invention will be explained using examples and in comparison with comparative examples, but it goes without saying that these examples are merely illustrative of the present invention and do not similarly limit the present invention itself.

<Example> First, steels 1 to 34 having chemical compositions as shown in Table 1
Welded.

Next, from these steels, outer diameter: 12
7sφ, wall thickness: 12.7M, tensile strength approximately 10100
A perforating gun material with an N/- level was created and its perforation properties were investigated.

The results of this investigation are shown in Table 2.

In order to evaluate the perforation property, a scalloped test piece with dimensions and arrangement as shown in Fig. 6 was cut out from the Bar 7 orating gun material, and a powder whistle of the same type was placed inside the scalloped tube 11. After installing Barf A Lator 8, it was ignited at the same time, and the condition of the hole that was created,
This was done by investigating the occurrence of cracks and the presence or absence of rupture. Here, in cases where the total gunpowder 1 is 114g or more shown in Table 2, the inside of all six scan O-butbs, and in cases where the total gunpowder temperature is 96g or less, the seal end (see Figure 6) The test was carried out by mounting a perforator inside each of the three scallops in the row at the same distance from the sealing plug (12).

From the results shown in Table 2, it is clear that the steel of the present invention has extremely good bar 7 orientation properties.・
...Minor cracks occur inside and outside the scallop tube, ×...rupture.

Therefore, it can be seen that it is fully suitable for use as a steel for perforating guns.

Therefore, next, inventive steels 1, 4, 11, 21° and 27°
When we created an actual perforating gun with scallop processing using Comparative Steel 28 and conducted field tests, we found that the perforating gun made of Comparative Steel 28 was severely damaged. , invention steel 1
, 4.11°21 and 27, clean holes were formed and no cracks occurred.

These results are also noteworthy as they indicate that the perforation properties in the field can be sufficiently evaluated by the tests shown in Table 2 and FIG.

<Industrial Utility> As explained above, according to the present invention, steel for perforating guns with extremely good perforation properties can be obtained at a relatively low cost, making it suitable for oil and natural gas mining operations. This can further improve the smoothness and stability of
This provides a drain that is extremely useful in industry.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of an oil well for oil extraction, Figure 2 is a schematic diagram showing the structure of a perforator, and Figure 3 is a schematic diagram of the main parts of a conventional perforating gun with a perforator attached. , Figure 4 is a schematic diagram that does not show the situation at the moment when the perforator is ignited and a hole is made during perforating work. FIG. 5(a) is a longitudinal cross-sectional view thereof, FIG. 2(b) is a cross-sectional view thereof, and FIG. FIG. 6(a) is a schematic view of the test piece used, and FIG. 6(a) is a longitudinal sectional view thereof, and FIG. 6(b) is a sectional view taken along line AA in FIG. 6(a). In the drawing. 1...Casing, 2...Oil layer. 3... Layer to cement 1, 4... Excavation tower. 5...Cartridge, 6...Gunpowder. 7... Copper plate liner. 8...Perforator. 9...Perforating gun. 10...Jet flow. 11...Scallop (dent). 12... Seal plug. Applicant Sumitomo Metal Industries Co., Ltd. Agent Tomi 1) Kazuo and 2 others No. 1 m Kaya 2 map Hata 3 map

Claims (4)

[Claims] (1) Weight percentage: C: 0.20-0.50%, Si: 0.05-0.75%, Mn: 0.30-1.80%, Ni: more than 0.50-2.00 %, Cr: 0.50-1.50%, one or more of Mo or W: 0.10-0.50% for Mo+1/2W, Se: 0.001-0.100%, Al: 0 .005 to 0.100%, Fe and unavoidable impurities: the remainder, and the content of P and S in the impurities is P: 0.025% or less and S: 0.015% or less, respectively. Steel for perforating guns with excellent perforation properties. (2) Weight percentage: C: 0.20-0.50%, Si: 0.05-0.75%, Mn: 0.30-1.80%, Ni: more than 0.50-2.00 %, Cr: 0.50-1.50%, one or more of Mo or W: 0.10-0.50% for Mo+1/2W, Se: 0.001-0.100%, Al: 0 .005 to 0.100%, and further contains Cu: 0.50% or less, Fe and inevitable impurities: the remainder, and the content of P and S in the impurities is P: 0.0. 0.025% or less, S: 0.015% or less, steel for perforating guns with excellent perforation properties. (3) Weight percentage: C: 0.20-0.50%, Si: 0.05-0.75%, Mn: 0.30-1.80%, Ni: more than 0.50-2.00 %, Cr: 0.50-1.50%, one or more of Mo or W: 0.10-0.50% for Mo+1/2W, Se: 0.001-0.100%, Al: 0 .005 to 0.100%, and further contains V: 0.01 to 0.10%, Nb: 0.005 to 0.100%, Ti: 0.005 to 0.100%, B: 0. 0003 to 0.0050%, consisting of Fe and unavoidable impurities: the remainder, and the content of P and S in the impurities is P: 0.025% or less, S: 0.015% or less, respectively. Steel for perforating guns with excellent perforation properties. (4) Weight percentage: C: 0.20-0.50%, Si: 0.05-0.75%, Mn: 0.30-1.80%, Ni: more than 0.50-2.00 %, Cr: 0.50-1.50%, one or more of Mo or W: 0.10-0.50% for Mo+1/2W, Se: 0.001-0.100%, Al: 0 .005 to 0.100%, and further contains Cu: 0.50% or less, V: 0.01 to 0.10%, Nb: 0.005 to 0.100%, Ti: 0.005 to 0.100%, B: 0.0003 to 0.0050%, Fe and inevitable impurities: the remainder, and the content of P and S in the impurities is P: 0.025%, respectively. Hereinafter, a perforating gun steel with excellent perforation properties, characterized in that S: 0.015% or less.