RU163129U1 - DOCKING ASSEMBLY OF CORE RECEPTION PIPES WITH INTERMEDIATE CORE HOLDER - Google Patents

Abstract

The utility model relates to devices for drilling wells with coring, to coring shells (CBS), and in particular to devices for holding coring in core collection pipes (CPT) directly during the selection process and designed for drilling vertical and inclined deep oil and gas wells with sampling core. The technical task is to increase the reliability of gripping the upper part of the core column in case of its fracture along an oblique system of cracks located at an acute angle to the axis of the well. The technical result is achieved by the fact that the docking unit of the core-receiving pipes with an intermediate core holder, including the central coupling coupling KPT, and core-receiving pipes connected by it as a composite insert, freely suspended on the bearing unit inside the CBS, having a nipple thread on the one hand and a coupling on the other, with the core holder placed in a tuck made inside the housing of the KPT centralizer coupling with the formation of an annular protrusion, while the intermediate core holder consists of a tightly mounted the handle of a split support ring, with an inclined end surface with a magnet installed in its body in the place where the height of the support ring is the smallest, and a core-gripping element made in the form of a movable ring sleeve with parallel ends, the inner surface of which is made in the form of a cone placed by a large base cone on the support ring with the possibility of radial, circular and axial movements relative to the support ring, and the angle α of the generatrix of the cone is greater than or equal to the angle β of the inclination of the end surface a support ring, the movement of which up the tuck is limited by a retaining ring-sleeve made in the form of a cylinder with an external nipple thread that is responsive to the coupling thread of the centralizer coupling. An additional technical solution that ensures the prevention of core spells in CBS uses the placement of an intermediate core holder in each coupling along the entire length of a single or composite CBS. A technical solution is provided in which shortened core-receiving pipes are used in WWTP, the total length of which, taking into account the connecting couplings, is proportional to one or several (two, three, four) standard-length core-receiving pipes of a composite WWTF. Thus, the technical result is achieved - increasing the efficiency of the elongated WWTF under the geological conditions of anisotropic-fractured rocks, achieving a higher driving penetration, while minimizing STR in anisotropic-fractured carbonated silicified rocks. 3 points of the formula, 2 illustrations.

Description

The utility model relates to devices for drilling wells with coring, to coring shells (KOS), and in particular to devices for holding coring (core holders) in core collection pipes - (CPT) directly in the process of coring, in the selection cycle and intended for drilling vertical and inclined deep oil and gas wells with coring.

It is known that coring is one of the main ways to obtain the necessary geological information for the study of oil and gas horizons. The progress of technical solutions in the field of coring is developing along the path of increasing the effective length of the WWTP, from 6-7 to 28-30 m or more. It is assumed that an elongated BOC allows proportionally to the number of sections to reduce the number of tripping operations from the depths of 2-3 and more than thousand meters, increasing the effective time of deepening the well with coring, and reducing the time spent on STR, reduces the cost of coring cycle in the total cost of a deep well through an increase in commercial drilling speed. This elongation of the CBS entails a proportional increase in the length of the composite core-receiving pipes (CPT), which are joined by couplings, which also play the role of centralizers of the CPT. However, the use of an elongated KOS arrangement is ineffective in conditions of coring by anisotropic-fractured rocks. When a well is drilled at an acute angle (0> α> 90 °) to the plane of fracture anisotropy, the system core plugs in the WWTF, in the core-receiving pipes, reduce the effectiveness of using extended WWTF to zero (Table 1). Thus, for anisotropic-fractured rocks, the technical solution to increase the length of the WWF (through the joining of several (2-3-4) sections of core-receiving pipes) is characterized by low efficiency, this is its main drawback.

We illustrate the problem of core sampling in anisotropic-fractured (angle of incidence of cracks 75-80 °, or 35-55 ° to the axis of the core) carbonate reservoir rocks by the example of the oil and gas condensate Yurubcheno-Tokhomskoye field (UTM), one of the largest fields in Eastern Siberia, unique in its properties and not even having close analogues in Russia and the world [1]. In the fractured Riphean dolomites, the main reserves of oil, gas and gas condensate have been explored. In the geological section of the UTM sedimentary cover, the most problematic object for drilling wells with coring for many years remains precisely the target object - productive oil and gas saturated anisotropic-fractured carbonate deposits of Riphean.

Thus, according to the results of core sampling in four UTM deviated wells, [Syraev R.U., et al. Core sampling in deviated pilot shafts in anisotropic carbonate Riphean reservoirs at the Yurubcheno-Tokhomskoye oil and gas condensate field. 02.2014. //// “Actual problems of the geology of oil and gas of Siberia”: Materials of the All-Russian Scientific Conference of Young Scientists dedicated to the 80th anniversary of Academician A.E. Kontorovich. Novosibirsk: (Electronic Edition) / INGG SB RAS, 2014. http://ems2013.ipgg.sbras.ru, free]:

- The opening angle of the Riphean dolomites by an inclined shaft in two wells was about 45 °, in the other two - about 25 °, the total penetration with coring was 416.9 m, the linear core removal was 94.6%. When comparing flight indicators, a decrease in the flight length by 2–3 times in the reef is convincingly recorded, and a multiple increase in the number of flights. During drilling in the riphean along the destroyed fractured zone, the upper part of the core column is scrapped and the core pipes are displaced down, a spell occurs, as a result of which the mechanical drilling speed drops to 0.

- The average length indicators of a shortened (incomplete, with a spell) flight (185.9 m out of the drilled 416.9 m) along four trunks in the riphean amounted to - 4.07 m. The average take-off for the voyage is 3.92 m, which is - 96.93%. Analysis of the average penetration per flight for all four inclined shafts shows a sharp reduction in the length of the flight due to core spells. systemic reduction in penetration per flight.

- The data on core sampling in exploratory wells, which were able to be compared (wells XX-Yurubchenskaya, X-Terskaya), clearly fit into the established pattern - after opening the Riphean penetration for the flight decreased by several times. Fluctuations in the length of the flight to the core spike in the CBT do not exceed 6.0-6.5 m and depend on the degree of fracture of the selected carbonate rocks, as well as on the angle of incidence of the fracture revealed by the well during drilling. This dependence is also observed for all four drilled pilot trunks, and reflects the geological features of the coring object - anisotropic-fractured cavernous dolomites of the Riphean weathering crust. For example, almost in the sampling interval of 2600.82-2610.48 m, five runs were completed in the KhKHU well; in the sampling interval of 2816-2823 m in the well. CAM - three flights, but the percentage of core removal required by the Project is provided.

The practice of coring in deviated wells has been established [R. Siraev, et al. Technical aspects of drilling with coring in anisotropic carbonate Riphean reservoirs at the Yurubcheno-Tokhomskoye oil and gas condensate field // Geology and Minerageny of Central Asia. Materials XIX international. scientific and technical Conf. - Irkutsk: Publishing house of IRNITU, 2015 .-- 344 p. 271-276.] That the core column spell occurs when a core fragment falls down the core receiver pipe under the action of gravity (Fig. 1). In other words, there is a comprehensive decrease in the efficiency of the elongated WWTP, which leads to the inability to continue coring. The need for unscheduled hoisting operations (STR) increases the total time of well drilling with coring, and the commercial drilling speed is reduced by a factor.

It follows from the given example that in practice the use of the standard set of WWTF allows for core sampling in anisotropic-fractured dolomites to be carried out with an offset of about 90-95% only by short flights, and the extension of the WWTF to 14-21-28 m does not make sense without finalizing its design. Such a refinement is needed that would allow the core column to be held inside the core receiving pipes, distributing the weight of the column into relatively equal parts, preventing it from breaking and falling down with the pin.

Known core drills of various designs, the main purpose of which is the capture and retention of the core column (for example, US patent No. 3139945; RU 1808988 A1), or the capture, separation and retention of the core in a core collection pipe (for example, patent RU 2182216; RU 2276718 C1). For core sampling of intermittent rocks of various hardness, the combined layouts of core types of different types are used (Johansen K.V., Sputnik burovika. Reference book. - Simferopol: Publishing House Business Inform, 2014, 488 p.).

A common drawback of these devices for capturing, tearing off and holding the core column during drilling with core sampling is that they are technically designed in one area of the WWTF, in its lower part, in the core drill body, and placed directly behind the drill head. Here, in the lower part of the WWTF, the operation of capturing and holding the core column, which entered the CBT, is implemented.

Known universal core explorer (US Pat. RU 2276718 C1), comprising a body, the diameter of the upper part of which is less than the diameter of its lower part with the formation of an annular protrusion, a support ring with an inclined end surface and a core gripping element made in the form of a floating sleeve with parallel ends, the inner surface which is made in the form of a cone, placed by a large base of the cone on the support ring with the possibility of radial, circular and axial movements relative to the support ring, and the angle α forming to the diameter is greater than or equal to the angle β of the inclination of the end surface of the support ring, a magnet is installed in the support ring, and a hole is made in the core core body for supplying a jet of washing liquid to the end face of the sleeve, the magnet being installed in the body of the support ring where the height of the support ring is the smallest and the hole for supplying a jet of washing liquid to the end of the floating sleeve, made in the housing, is located on the same line with the magnet parallel to the axial line of the core core body. The disadvantage of this core explorer as a “core-retaining” device or core holder is its single placement in the core collector assembly, in the lower part of the WWT, which does not allow the device to work to hold the top of the core column when it is broken in the CBT, and therefore does not prevent the core from wedging in the CBT. The lower placement of the analog core holder in the WWTF entails the transfer of the full weight of the core column, which favors the core sticking in the CBT when it is broken and displaced down due to gravity (in a vertical well) or its vertical component (in an inclined well), which is especially typical for elongated CBS.

A technical solution is known (Pat. RU 1819980), involving the placement of additional intermediate core holders in the CBT. So, the core collection pipe is equipped with elastic elements, the ends of which are inclined upward along the core, and the core collection pipe is eccentric. The disadvantage of this solution is the insufficient reliability of holding a smooth core column of high strength (silicified dolomite, dolerite, granite) and heavy weight.

The closest technical solution involves the placement of a rubber core holder in a recess, which is carried out inside the housing of the central coupling of the KPT (I.K. Knyazev. Driller on coring. // M., Nedra, 1981, 102 pp.). In fact, it is the placement of the intermediate core holder in each docking unit of the CPT that solves the problem of the “upper” retention of the core column. Considering the docking assembly, namely, the KPT centralizer coupling connecting the composite liner of the core-receiving pipes, freely suspended on the bearing assembly inside the CBS, having a male thread on the one hand and a male thread with a recess inside the coupling body, due to which an annular protrusion is formed into the body (housing) of the coupling-centralizer of KPT, we propose to take this technical solution as a prototype. However, the main drawback of the known rubber core holder, which is inserted into the undercut of the coupling, is the limitation of efficiency when holding large diameters of 80 mm and 100 mm of a dolomite core over an extremely strong cylinder, and of a large weight, which, when exceeding the weight above the critical (smooth and extremely strong core cylinder surface, determines weak coefficient of friction) will lead to disruption, core slippage.

The claimed technical solution is aimed at developing an intermediate core holder and at placing it in the docking unit - connecting couplings-centralizers of core receiving pipes, thereby achieving 100% increase in the reliability and overall performance of elongated WWF in difficult geological conditions of coring in anisotropic-fractured rocks, prone to fracture along oblique planes of fracturing through achieving higher penetration per flight, the exclusion of unscheduled STR due to core plugs in the CBT, and in echnom ultimately reduce costs in the construction of deep wells by increasing commercial speed coring cycle. The technical result is an increase in the efficiency and reliability of the proposed device.

The claimed technical solution should:

- do not impede the core movement up along the CBT while deepening the well with selection;

- distribute the weight of the core column in the CBT into several relatively equal parts in a long (elongated) WWT, with the transfer of each part of the weight to the core grab element, thus preventing scrap and core destruction along oblique cracks under the core's own weight, and excluding the removal of each core column down during core cracking (if there are more than two fragments) under the influence of gravity or due to vibration of the WWTF, while also preventing core fragments from being split up in the core collection pipe.

- include in the design of the CPT, several devices of the same type for holding the core column by its upper part in order to ensure the implementation of the “upper retention” of the fragment when the core is broken along an oblique crack under the influence of the core's own weight and exclude the upper movement (which is higher than the fracture, see Fig. 1) part of the core column down and its subsequent rasklinka in CBT;

The stated technical problem is solved by the fact that the proposed utility model is developed according to technical solutions to improve the docking unit - the connecting sleeve of the core receiving pipes and the intermediate core holder located in this node and involves the multiple placement of this unit from bottom to top along the core shell, ensuring the operation of the core column closest to the "head" core holder at the time of fracture, core destruction along oblique fracture planes.

The technical result is achieved by the fact that the docking unit of the core-receiving pipes with an intermediate core holder, including the central coupling coupling KPT, and core-receiving pipes connected by it as a composite insert, freely suspended on the bearing unit inside the CBS, having a nipple thread on the one hand and a coupling on the other, with a core holder placed in a recess made inside the housing of the KPT centralizer coupling with the formation of an annular protrusion, while the intermediate core holder consists of a tightly installed A recess of a split support ring, with an inclined end surface with a magnet installed in its body in the place where the height of the support ring is the smallest, and a core gripping element made in the form of a movable ring sleeve with parallel ends, the inner surface of which is made in the form of a cone placed by a large base cone on the support ring with the possibility of radial, circular and axial movements relative to the support ring, and the angle α of the generatrix of the cone is greater than or equal to the angle β of the inclination of the end surface a support ring, the movement of which upward in the recess is limited by a retaining ring-sleeve made in the form of a cylinder with an external nipple thread that is reciprocal with respect to the coupling thread of the centralizer coupling.

At the same time, an intermediate core holder is placed in each connecting coupling-centralizer of the KPT along the entire length of a single or composite - elongated KOS.

Moreover, shortened core-receiving pipes are used in WWTF, the total length of which, taking into account the connecting couplings, is proportional to one or several - two, three, four - a standard length of a single or composite pipe - elongated WWTF.

The presence of these signs indicates the compliance of the proposed technical solution to the criterion of "novelty." The application contains all the means by which it is possible to implement a utility model that meets the criterion of "industrial applicability".

The essence of the utility model is illustrated by drawings, where in FIG. 1. Reflects the pattern of the core column splices in core-receiving pipes (CPT) for breaking along an oblique crack and shifting the upper fragment down.

1. - the upper and lower fragments of the core column;

2. - core receiving pipes;

3. - direction of movement of the upper fragment (down);

4. - The plane of the broken spell.

In FIG. 2. the section of the docking assembly is reflected, including a KPT centralizer coupling with an intermediate core holder, and core-receiving pipes connected by it, where 1 are composite core-receiving pipes (KPT); 2 - casing of the centralizer coupling connecting the sections of the CPT; 3 - recess in the body of the coupling-centralizer; 4 - annular protrusion; 5 - split support ring; 6 - core gripping element - movable sleeve; 7 - a lock ring sleeve; 8 - magnet; α is the angle of the generatrix of the cone; β is the angle of inclination of the end surface of the support ring.

The inventive design of the utility model is graphically presented in the drawing (see Fig. 2), which shows the docking assembly of the KOS core-receiving pipes joining the upper and lower sections of the KPT-1, connected by the KPT-2 centralizing sleeve, and the intermediate core holder, located in the coupling body a centralizer in a recess 3 with an annular protrusion 4, which consists of a split support ring 5 that is tightly installed in the recess of the groove with an inclined end surface and the main working structural element - a core grabbing element in the form of a movable ring w flanges 6 with parallel ends and a conical inner profile made in the form of a cone facing down with the base, and the angle α - forming the cone is greater than or equal to the angle β - the inclination of the end surface of the support ring 5, the movement (movement) of which upward along the annular space of the recess in the coupling -centre is limited when the core column moves upward when the well is deepened with core sampling by a fixing element - a retaining ring-sleeve 7 on the thread, and a magnet 8 is placed in the body of the support ring 5, and the magnet is installed in the body of the support ring rings where the height of the support ring is the smallest.

The device operates as follows. During the operation of the claimed design, when deepening the well with coring, the rock column enters the core-receiving pipes 1 into the cavity of the core-receiving pipe and the centralizer coupling 2, then the core column moves up along the CPT and sequentially passes through each node of the claimed design of the docking unit: KPT centralizer - intermediate core holder (see Fig. 2), located in each KPT docking sleeve. At the same time, the working element - the movable sleeve 6 passes the core column up as the well deepens. In the event of a core column breaking along an oblique plane of a crack in the rock, the upper core fragment is fixed (intercepted) by the first of the centralizer – core holder assemblies, which at that moment are located in the CPT docking sleeve below the “core head”, preventing the core fragment from moving down and its wedging. The movement of the upper core fragment down and serves as a warning of the spell in the area of oblique fracture along the crack. At the same time, each node located lower along the CBS is triggered on hold. As a result, the movable sleeve 6 operates on the principle of a washer occupying a “skew” position on the cylindrical body. Subsequently, the core is delivered to the surface, the removal of the fixed debris is carried out after untwisting the CBT and the retaining ring-bush 7.

Thus, the technical result is achieved — increasing the efficiency and reliability of the elongated WWT operation in mining and geological conditions of coring in anisotropic-fractured rocks, prone to fracture along oblique fracture planes by achieving higher penetration for one run, elimination of unscheduled STR due to core splinters in CBT and, ultimately, cost reduction during the construction of a deep well by increasing the commercial speed in the coring cycle.

Claims (3)

1. Docking assembly of core-receiving pipes (KPT) with an intermediate core holder, including a KPT centralizer coupling and core-receiving pipes connected by it as a composite insert, freely suspended on the bearing assembly inside a core pickup (KOS), with a nipple thread on one side and on the other - coupling, with the core holder placed in the recess, made inside the housing of the KPT centralizer coupling with the formation of an annular protrusion, characterized in that the intermediate core holder consists of a tightly mounted the groove of a split support ring with an inclined end surface with a magnet installed in its body at the place where the height of the support ring is the smallest, and a core-gripping element made in the form of a movable ring sleeve with parallel ends, the inner surface of which is made in the form of a cone, placed by a large base of the cone on the support ring with the possibility of radial, circular and axial movements relative to the support ring, and the angle α of the generatrix of the cone is greater than or equal to the angle β of the inclination of the end surface support ring, the movement of which is limited upwards by a retaining ring recess-sleeve designed as a cylinder with an outer threaded nipple, the response with respect to the coupling-thread coupling centralizer. 2. The docking unit according to claim 1, characterized in that the intermediate core holder is located in each coupling sleeve-centralizer of the KPT along the entire length of a single or composite - elongated KOS. 3. The connecting unit according to claim 1, characterized in that the WWT uses shortened core receiving pipes, the total length of which, taking into account the connecting couplings, is proportional to one or several - two, three, four - a standard length of a single or composite pipe of an elongated WWT.

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