USE OF PRESSURIZED MEDIUM IN DRILLING

Abstract: Use of a pressurized medium in a drilling apparatus for drilling a hole in the ground. The drilling apparatus comprises a drilling device (1), such as a down-the-hole drill or the like, the first end thereof having a drilling means, such as a drill bit (2), and the second end thereof being at least connectable by joining means (3) with one or more separate drill rods (4) for increasing the drilling depth of the drilling device in the direction of the longitudinal axis (k); scavenging means (8) for removing drilling waste generated by the effect of the drilling means (2); and a support frame (9) at least indirectly supported by the ground. The drilling device (1) is arranged to be driven by a feeding movement in the direction of its longitudinal axis (k) and by a to-and-fro or corresponding percussion movement as well as by a rotational movement or the like in relation to its longitudinal axis (k). The percussion means (6) of the drilling apparatus for providing the percussion movement of the drilling device (1) are arranged to be hydraulically operated by an organic, oil-based pressurized medium (m) derived from a natural biological metabolism, such as a vegetable oil, an animal oil, or the like.

Description: Use of pressurized medium in drilling The invention relates to the use of. a pressurized medium particularly as the pressurized medium for the percussion means in a drilling device of a drilling apparatus for drilling a hole in the ground, whereby the drilling apparatus comprises at least: - a drilling device, such as a down-the-hole drill or the like, the first end thereof having a drilling means, such as a drill bit or the like, and the second end of the same being preferably connectable with one or several drill rods for increasing the drilling depth of the drilling device, which drilling device is at least partially arranged to be driven by a to-and-fro or corresponding percus¬ sion movement, whereby the drilling device comprises at least percussion means for generating the percussion movement, which means are arranged to be driven by a pressurized liquid medium supplied through a first flowing arrangement, preferably scavenging means for removing drilling waste generated by the effect of the drilling means, the scavenging means being arranged to supply a scavenging agent through a second flowing arrangement, preferably in connection with the drilling means of the drilling device, and a support frame being at least indirectly supported by the ground. Apparatuses of the type described above, using pressur¬ ized air, have been known for a long time and are widely used in mineral industry. It is an advantage of a drilling device to be placed down the hole that the percussion impact is directed to the drill bit, whereby the energy losses and unnecessary wearing of the components of the apparatus can be reduced in comparison with solutions having the drilling device placed at the rear end of drilling rods. Conventionally in drilling devices driven by pressurized air, pressur¬ ized air is used also for scavenging the crushed aggregate. However, it is not advantageous to drive a drilling device by pressurized air, e.g. because this requires a compressor unit with a very high capacity. Furthermore, the efficiency of a pneumatic system is clearly lower than that of a hydraulic system. The use of a hydraulic drilling machine is known e.g. from the published international application PCT/EP89/00256. In the solution of the above applica¬ tion, the driving unit of the drill rod, driven by a pressurized medium, conveys a to-and-fro rotational motion to the drill rod, as distinguished from the rotational motion conventionally used. Thus, hoses are arranged between the drill rod and the walls of the drill hole, whereby upon inserting or removing rods, hoses are fed into the hole or reeled in from the hole. For achieving an optimal drilling efficiency and for saving the hoses, the angle of rotation of the drill rod is preferably limited to the range 180- 360°. For minimizing the wearing of the hoses, an embodiment is presented in the publication where the drill rod comprises two outwards open longitudinal channels in which the hoses are inserted for feeding in and out the pressurized oil of the drilling machine to be placed in the hole. The hydraulic hoses are thus preferably inside the circle of the drill rod. Scavenging air is preferably input through a hollow drill rod. The solution of the above-mentioned publication is not very advantageous in practice, because massive machinery is required for the handling of hoses. Both hoses must be provided with reeling rolls and driving units, their need of space being determined by the depth of the hole to be drilled. It is naturally difficult to handle the hoses in the drilling situa¬ tion, whereby careless installation may result in environmental damage in case of damage to the hoses. Naturally, hoses of different lengths must be used or hoses must be fitted with joints when holes of dif¬ ferent lengths are drilled, which also results in environmental risks. The use of pressurized medium according to this invention is intended for achieving a decisive improve¬ ment to the disadvantages described above and thus to improve substantially the state of art in the field. For achieving this aim, the invention is primarily characterized in that the pressurized medium used is an organic, oil-based pressurized medium derived from a natural biological metabolism, such as a vegetable oil, an animal oil, or the like. On the other hand, the use of vegetable or animal oils in drilling is in a certain sense previously known. However, the oils of the present type have not been previously used as a hydraulic fluid in any kind of drilling and thus naturally not particularly as the pressurized medium of the percussion means either. For example in the U.S. Patent 4,631,136 and in the GB application 2,246,802, vegetable and animal oils have been used in drilling as a scavenging agent only. Further, the use of vegetable oils as a hydraulic fluid has been studied and developed for a long time, articles on this being found from years as early as 1983 and 1984. However, for almost ten years, no artisan in the field has been able to apply the use of an organic pressurized medium particularly in down-the-hole drilling of this context, or the like. The most important advantages of the use of the pressurized medium according to the invention are its simplicity and safety, which features are essential requirements for working in a both technically ad- vantageous and environmentally safe way. The invention makes it possible to feed the pressurized medium in an integrated way through the drill rods, further facilitating the insertion and removal of drill rods quickly and easily, whereby it is also possible to use the continuous rotational movement of the drilling device in one direction. Consequently, the use of the pressurized medium according to the invention provides an advantageous technical application, whereby the operation of the drilling device is further optimized in an environmentally safe way. In the other dependent claims, advantageous applica¬ tions of the use of the pressurized medium according to the invention are presented. In the following description, the invention is il¬ lustrated in detail with reference to the appended drawings, in which Fig. 1 shows a side view of an advantageous drillingapparatus applyingthepressurized medium of the invention, Fig. 2 shows a partial longitudinal cross-section of parts connected with each other by joining means, Fig. 3 shows a partial longitudinal cross-section of parts separated from each other, and Fig. 4 shows an advantageous cross-section of parts of the drilling apparatus. Figure 1 shows an advantageous application of the drilling apparatus applying the pressurized medium of the invention. The drilling apparatus comprises a drilling device 1, such as a down-the-hole drill or the like, the first end thereof having a drilling means, such as a drill bit 2; scavenging means 8 for removing drilling waste generated by the effect of the drilling means 2; and a support frame 9 which is at least indirectly supported by the ground and fitted with feeding means 10a for providing the feeding movement of the drilling device 1 and with motion means 10b for providing the rotational movement or the like of the drilling device 1. The drilling device 1 is arranged to be driven by a feeding movement in the direction of its longitudinal axis k and by a to-and-fro or corresponding percussion movement as well as by a rotational movement or the like in relation to its longitudinal axis k. The percussion means 6 of the drilling apparatus for providing the percussion movement of the drilling device 1 are arranged to be hydraulically operated by an organic, oil-based pressurized medium m derived from a natural biological metabolism, such as a vegetable oil, an animal oil, or the like. The second end of the drilling device 1 is connected by joining means 3 with a separate drill rod 4 for increasing the drilling depth of the drilling device 1 in the direction of the longitudinal axis k. Further, the drilling apparatus comprises a first flow arrange¬ ment 5 for supplying hydraulic fluid m and a second flow arrangement 7 for supplying scavenging agent 1 to the drill bit 2 functioning as the drilling means of the drilling device 1. Using a biodegradable pressurized medium according to the invention, it is possible to supply the pressurized medium to the percussion means by a flowing space integrated in the drill rod. In the use of conventional hydraulic oils, this kind of a solution is not par¬ ticularly advantageous nor even allowed in all condi¬ tions, because possible leaks cause immediate problems, such as contamination of the environment. Thus in the applications shown in Figs. 1-4, the first flow " arrangement 5 and the second flow arrangement 7 are arranged substantially in connection with the drilling device 1 and the one illustrated drill rod 4 to provide for the movement of the drilling device 1 in the drilled hole. The drilling device 1 is thus moved preferably by the motion means 10b in a continuous rotational movement w in one direction. The second flow arrangement 7 comprises a flowing cavi¬ ty 7a integrally arranged with the drilling device 1 and the drill rod 4. Thus the first flow arrangement 5 comprises in a corresponding manner preferably two flowing cavities 5al, 5a2 preferably integrally arranged with the drilling device 1 and the drill rod 4. Figures 2 and 3 illustrate the joiningmeans 3 connect¬ ing the drilling device 1 and the drill rod 4, as well as the function thereof. The joining means 3 are formed by a threaded coupling, and the first flow arrangement 5 and the second flow arrangement 7 are arranged as flowing cavities 5al, 5a2, 7a on top of each other in the drilling device 1 and the drill rod 4 in the radial direction. Further, the joining means 3 comprise coupling means 3a which close the connecting units 5yl, 5y2 that are opened when the said parts 1, 4 are disconnected. Upon disconnecting the parts, it is thus possible to keep the hydraulic fluid m inside the parts which, in principle, function as deposits. When the parts are reconnected, the hydraulic fluid is immediately available for use by the drilling device. Before disconnecting the parts, they ca naturally be emptied from the hydraulic fluid m e.g. by pressurized air or in a corresponding manner. Thus upon reconnecing the parts, it. is, however, necessary to feed the hydraulic fluid before the actual use of the drilling device. As shown in Fig. 4, the flowing cavity 7a for scaveng¬ ing agent 1 is arranged on the perimeter of the parts 1, 4 to surround the first flow cavity 5al arranged centrally for the hydraulic fluid m and the second flow cavity 5a2 surrounding the same. As shown in Figs. 2 and 3 in more detail, the coupling means 3a are arranged to be self-operated by spring suspension f in connection with one end of the drilling device 1 and both ends of the drill rod 4 upon connect¬ ing and disconnecting the said parts 1, 4, whereby the coupling means 3a are formed by counterparts to be placed within each other (Fig. 2) , whereby one of the fitted parts has a recess 3al and the other has a projection 3a2. Thus the corresponding flow cavities 5al, 5a2 of the parts 1, 4 are connected with each other by flow units 3bl, 3b2 in the counterparts 3al, 3a2. Further, the counterparts 3al, 3a2 of the coupling means 3a are provided with closing parts, whereby one of the counterparts has a slide part 3cl and the other has a socket part 3c2 at the end. Thus in the parts separated from each other (Fig. 3) , the joint units 5yl, 5y2 of the flow cavities 5al, 5a2 containing the hydraulic fluid m are closed by the closing parts 3cl, 3c2. In an advantageous application, the pressurized medium m is an organic, such as rape-oil-based, hydraulic fluid or the like. As a result of continuous development, it has further been found that an advantageous pressurized medium is a hydraulic fluid based on a vegetable oil ester; an example of this is a synthetic ethyl ester. It is clear that the invention is not limited to the applications described above but that it can be varied within the idea even to a great extent. First, the hydraulic fluid of the percussion means can be supplied by hoses or the like. Correspondingly, one of the flow arrangements of the scavenging means can be formed of e.g. two channels, one for supplying the scavenging agent and the other for suction through the inner space of the drilling device and the drill rod. In a corresponding manner, the rotational movement of the drilling apparatus can be arranged to and fro, although this requires more complicated and insecure control engineering than the solution presented above.

Claims: Claims : 1. Use of a pressurized medium, such as an organic, oil-based pressurized medium derived from a natural biological metabolism, such as a vegetable oil, an animal oil, or the like, particularly as the pres¬ surized medium (m) for the percussion means (6) in a drilling device (1) of a drilling apparatus for drilling a hole in the ground, whereby the drilling apparatus comprises at least: - a drilling device (1) , such as a down-the-hole drill or the like, the first end thereof having a drilling means (2) , such as a drill bit or the like, and the second end of the same being preferably connectable with one or several drill rods (4) for increasing the drilling depth of the drilling device (1) , which drilling device (1) is at least partially arranged to be driven by a to-and-fro or corresponding percussion movement, whereby the drilling device (1) comprises at least percussion means (6) for gener¬ ating the percussion movement, which means are arranged to be driven by a pressurized liquid medium supplied through a first flowing arrange- ment (5) , - preferably scavenging means (8) for removing drilling waste generated by the effect of the drilling means (2) , the scavenging means being arranged to supply a scavenging agent (1) through a second flowing arrangement (7) , preferably in connection with the drilling means (2) of the drilling device (1) , and - a support frame (9) being at least indirectly supported by the ground. 2. Use of a pressurized medium according to claim 1, wherein the pressurized medium (m) is vegetable- based, such as a rape-oil-based hydraulic fluid or the like- 3. Use of a pressurized medium according to claim 1 or 2, wherein the pressurized medium (m) is a hydraulic fluid based on a vegetable oil ester.

Inventors: SJOEHOLM HARRI, WISAKANTO RISTO, SJOEHOLM, HARRI, WISAKANTO, RISTO
Applicants: SJOEHOLM HARRI, WISAKANTO RISTO, SJOEHOLM, HARRI, WISAKANTO, RISTO
Application year: 1993
Main classification: E21B4
IPC codes: C09K8, E21B4, E21B21