SU1339231A1 - Method of drilling holes under hazard of brine manifestation - Google Patents

Abstract

The invention relates to the drilling of oil and gas wells and improves the efficiency and reduces the total cost of well construction during the overflow from a pressure object in the conditions of the NS field pressure equations in the wellbore and subsequent isolation of the well. of the pressure object, as well as to ensure the possibility of extraction of pipes from the well noc. ie pzo.ttsii pressure object. To do this, first establish the fact of disproportionation, then form a comfort tight sealing bridge (WG1) in the annular space behind the pipe between the pressure object and the area of possible leaks. After the discharge of the discharge from the zone of possible leakage, but the pipes of the pipe work on the isolation of the discharge line. The formation of the RP is carried out by batch injection of cement mortar into the column of pipes with an exposure up to 3 (1, 1, and 3 n subsequent displacing of the portions into the pot) under pressure, which exceeds the pressure in the pressure object, i.e. after the descent of the pipe into a pipe below the base of the zone in () possible leakage. To form P1I isio.pp, they harden when they are replaced with (laccol and tampyr mud (1 outdated mixtures, for example, brinetopic C)). The modes of mixing, injection, and) and 1. Of the cement slurry are selected according to the defined conditions. Having established the fact of the absence of p |) IT1) ka; pipes, turn off pipes over PI1, 3 Cp iji-.ibi che (Oh

Description

The invention relates to the drilling of oil and gas wells, in particular to methods of drilling in salt-bearing formations with high-pressure tributaries of aggressive brines and can be used in the oil and gas industry and in exploration.

The purpose of the invention is to increase the efficiency and reduce the total cost of well construction during the overflow from a pressure object under conditions of unbalanced pressures along the wellbore and subsequent isolation of the pressure object.

The essence of the method of drilling wells in terms of possible brines, including the separate isolation of zones of possible leaks and possible brines, and the descent of the pipe string below the bottom of the zone of possible leaks, is opened together with a portion of the section including possible zones leaks; moreover, if the brines are not actually encountered, the further construction of the well is stopped without the descent and cementing of the separation column; in cases of occurrence of brines, preliminarily form an airtight separating 11rem1) 1 point in the annular space in the section of the trunk between the pressure object and 3 (L4 possible leaks, and work on the discharge of the o6iieKTa pipe from the area of possible leaks.

The formation of a separating jumper is carried out by batch injection of cement mortar into a column of pipes with their exposure to thickening and subsequent displacement of portions into the annulus under pressure in a pressure object, e. after lowering the pipe string below the area of possible leaks; portions of cement slurry are pumped and pumped into the cavity with a rupture in time, leave ka) a portion of cement slurry in the cavity of the pipes for maturation before entering the thickening phase, and the first and subsequent portions are marketed into the annular space behind the pipes the area of possible leaks and the pressure object to complete sealing of the (3) forming together with it and the jumpers.

Yes, they carry out the crushing of residual portions of cement mortar into the barrel and (or) pressure object, leaving or without leaving the cement glass in the pipes, and holding the cement mortar under pressure that exceeds the pressure in the pressure object, until the cement stone sets.

The modes of mixing, injecting and forcing cement mortar should comply with the following CONDITIONS:

1: 1 atv tn cxh i ar j

I 1cav. - (- tnpoj Tr. Schw .;

I 1zatv-1prod I, X Tzag Tn.skhv;

., 1i (prnt. |

where 1 shackle is the total time from the beginning of the first portion of the gate to the end of the last gate, including the interruptions in the gate, min;

t: iaBT- | 0

five

0

five

0

five

+ t ,,

the total time from the beginning of the first portion of the filling to the end of the last crushing, including interruptions in stopping and stopping the ripening of the cement mortar to the thickening stage, min;

Claims (4)

I 1at. + - | -1prod liar (n Tsprod the total time from the beginning of the mixing of the i-th portion of the cement raster to the end of the forcing of the i-th portion to the place of its setting, min; the beginning of the thickening of the cement slurry from the time of mixing, min (determined for a given cement under borehole conditions by laboratory); c is the time of the beginning of the setting of the cement mortar from the moment of mixing (in well conditions) min (determined by laboratory order). supply of cementing aggregates (propelling flow rate) when displacing the i-th portion of cement paste to the point of seizure, l / s; QnpHT, is the current flow rate from the pressure object before the i-th portion of the cement raster is pressed to the setting point, l / s. Depending on the specific geological and technical conditions and technological tasks, a drill string, a casing column or its part can be used as a tubing string and lowered into the well on drill pipes (section, liner, fly). The lower end of the pipe string can be installed both above the roof of the pressure object and below its sole. The overlap of the casing under pressure object allows the use of traditional technology for further well deepening after isolating the pressure object. Suspensions that harden when mixed with brines (for example, a cement-cement and polymer-cement mixtures) or thicken to a loss of pumpability (for example, a solvent-5-tonite mixture) can be used as cementing solutions for forming separating bridges. In specific geological and technical conditions, the grouting mixtures may provide additional technological advantages, such as the possibility of tubes to the stage of solidification and for setting the main mass of the first portion in the annular space; From the holding time of the overflow and: the pressure object in the annular space was stopped, which indicated the presence of resistance to the brine flow to the formed jumper; With 8 m pumping solution injected with a density of 1,750 kg / m, the drill string was filled to the mouth for 4 minutes, after which the pressure on the head increased abruptly to 8.0 MPa; by pumping an additional 4 m of the squeezing solution, the remnants of the first portion of the cement slurry were completely expelled from the drill string in 4 minutes, with iTOM, the overpressure on the die head from 8.0 MPa dropped to 3.0 MPa, and about ; 3 m of brine, which indicated a lack of vision. Just a cement {stone in the lintel and its incomplete sealing. When the pressure on the head was 3.0 MPa, the following was suspended: 1 intake for 7 minutes, then pumped into the pipes 0.5 m of squeezing fluid with a flow rate of 5; i / c: at STOM, the pressure of the iia head increased to 12.0 MPa and stabilized In the course of the second control stop, the tightness of the jumper was adjusted for 5 minutes (at the full absence of current from the annular space at the mouth) and forced to push the residual portion of the cement into the cavity of the well 1 below the pipe string (by pumping |) Astior density of 150 kg / m in pipes) with a flow rate of 10 - 12 l / s with a hundred at a pressure of 10.0–13.0 MPa, at that, noc.ie for setting 12 m, pressure abruptly B03p (jc, io up to 16.0 –18.0 MPa, and the remainder of the second portion of cement mortar ( the rest of the nr (; crush with a volume of 2.5 m to a total volume of 27.0 m according to the calculation) is crushed for pog, 1O penpe in brine volume;) at a pressure of 1e (P1I pa slab above the full surface of the mountain, On ПЗ () l pyopp1 1e of work from the beginning of the first portion of the shutter to the setting of the last portion of the last portion of the calculated interval, t (to the setting point) 172 minutes were spent. After 1G) ozp, the pressure in the pipes from 16.0 MPa was reset to atmospheric, they were convinced that there was no inflow from the pipes, and the pipes above the bridge were turned off. Example 2. In the process of drilling a deep prospecting well, when a 4960 m bottom was drilled, a gas-fueled object with an I pa- .uii HTOM H.iacTOBoro pressure of 2.15-100 m was found, the presence of KOTOpoi o in the context of this section is not appropriate,: 1). After her iaiiHH seal, the pressure in the annulus was relieved (increased to 22.0 LAPa, then jumped — Ko6pa3ti () decreased to 18.0 L1Pa; subsequent studies, the presence of interflux flows ()) over the trunk in the interval from the main object (4960 m) to the place of noriva (245 mm) casing, mon 0 five 0 five 0 five 0 five (3000 m) with a flow rate of 2.6 2.9, i / c 250 m / day). To carry out repair work in the well, it was necessary to temporarily isolate the pressure head o6ijeKT. Insulation works were carried out according to the proposed method, in order to ensure the possibility of extracting a noc tubing string, i.e., isolating a pressure object using a solvent-flowable mixture. The nominal diameter of the STB (), in the open interval of 4960 4600 m is equal to 161 m, the pipe string is represented by UBT 0 135 mm, 180 m long, drilling pipes 0 102 mm 1500 m and 0 140 mm - 2860 m, the lower end of the pipe string is r, iy6iiHe 4540 m in the shoe 194 mm shank. In order to temper wellhead pressures, a 6ypoBoii solution with a density of 1950 mg / m was pumped into the cavity of the drill pipes with a density of 1950 mg / m at the mouth of the pipes with a decrease to 9.0 MPa, the pressure in the annulus did not change significantly due to the large volume of the hydraulic cavity. Then noc was pumped into the cavity of the drill string. ie dovat. 1–1.5 m dptop, chive as a buffer liquid, 10.5 m with, 1 robeptonite mixture with a density of 1260–1280 kg / m and 0.7 m of diesel, with a pressure of 18–25 MPa, the insulating composition was forced to the lower end pacTtiopoM n, ioT of 1950 kg / m drill string and after displacing the buffer position of diesel fuel into the co-axle space (as evidenced, 1O lowering of the wellhead pressure by 4.5 .Vina) led to the formation of an insulating bridge in the annular prostration behind the pipes. Sell the first batch of 2.3 m of robentonite mixture with a volume of 1 m, 1 and in the drunk space above the nmp end of the pipes with a flow rate of 2.5, 3 l / s, at the beginning of the hole there was a decrease in wellhead pressure in the pipes (due to .t of robentonite mixture bo.-iee with heavy drilling mud), and then its growth by 2.0 2.5 MPa (due to thickening of the portion in the co, first space). / 1a, 1new | np increase in resistance, in the core space could lead to an increase in the back pressure on the pressure object, a decrease in its flow rate and a worsening of the mixture of the sol roentonite mixture with n.iac water. To improve the quality and reliability of work, isofolov.and technological reception porión (1st slip of ss), 1 robo-tononit mixture according to (). () 0.8 m with consumption of 2.5-3.0, 1 / s and a portion of ing selection of 0.3 0.5 m with a flow rate of up to 20 l // s with partial, and at the end (.sheratation and fully discharge. pressure in pipes. As the solvent of the solar roentonite mixture was released from the pipes the difference in injecting pressure and () mr) and no-step increased from 4.0 MPa noi. ic displacement of 2.9 m of a sol-bentonite mixture from pipes up to 28–30 MPa after a set point H (i m B The ability of the iz-treatment of co / yuina chazde pipes. The lamella of the permmex formed from the sob of the robsntonite mixture of nocjc insulation on the HCJpHoro (object. Example 1. At the stage of exploration and drilling, the area in accordance with the 1st () logical predictions was attributed to the conceptual basis in connection with which the design for the exploration wells provided for the descent of 324 mm of the intermediate column per 1700 m The average depth of the roof of the salt roof is 1 2560 m. In the first well within the limits of the salt solution there is no place, but in the second hole there is a bottom inlet. miu emerged emission |) acc (); ia start. 1Y1b) 1 m with a flow rate of 400 m / day; the initial naslat radiation was estimated at 2.25 2.27 Mda / / 100 m. After a few hours of self-discharge, the production rate decreased to 80, but the ratio of the severity | the water supply has increased to 2 g / l, the decision on the isopia of a high-sprayed instrument by the proposed method of p (i) t () in connection with y po3oii, the well control of the borehole mega, .1a casing and borI. 1H () TH KO.IOHH. Actual stock)} wellbore below the nodon area of possible leaks in the interval of the forma) o1 and 1np sealed jumper 66 () mm. L.1I (}) about the separation of the section, 1 time 1) 1 pitch 50 m high and the settlement of the insulation of the pressure object n.ia, it was planned to pump 17 m of the solution from the port cement with the beginning, first thickening 90 min and start. yum cxisa- 105 min Ei borehole 1) 1 x usi x and 18 m solution pz pklakosch chanopement - mixture (Hl llIC) with pach.yum zusteva-pp 120 min and start skvryvni 145 min. The volume of the cavity of the storm. 1P) 1x 27.5 m / 1l of observance of the conditions on the predlozheniya- M (shu way the modes of the shut-off injection and the pipe and the sale of the 1P1I pemeitic solution are planned following) in one way. Slugging and pumping into the pipes of the first portion of cement solution (17.m) in 45–50 min, uninterrupted in the shutter for 30–35 min, the burying and injection of the second norm (18m) in 30 min with simultaneous displacement in the annular space ripened to thickening of part of the first law; extracting in the pipes the remainder of the non-ripening portion for ripening for 10 minutes, and the remainder of the residue of the first portion into the annular space behind the corpses (to the place of seizure) at a rate of 15 20; i / c; counter, 11) | movers of the second portion of 0.3 0.5 .m every 11 | e 5 min until complete crossing of the jumper (setting of the cross section) and crushing of the second portion into the cavity of the well H) same pipes for isolating the pressure object with pressure 50 m cement glass in the pipes. C) The bulk volume of the product is 27.0. M () 6niee Isolation time not less than ItiO and not more than 200 missions. To achieve the desired value (To press the shutter, install Jl on the hydro-mix; 1n1) 1X funnels; but first Media-20 (with 20 tons of Northlaid cement for hot wells) 0 12 mm notes 1 th slan 20 (with 20 t SNTCs) 0 Hi mm. The given mode is set to take into account the possibility of self-digging of a wide range of cement pipe or pipes for 800 n (9 m) from the estuary. The density density of the cement) (1750 kg / m) ) and pacco.ia in co. p |) () - st |) and n st ve (1200 to g / m). Glorious descent of the storm below 1I) D (). zones in () smog} P) 1x leaks were installed on cement pipes 1tochnik 11uk), four a1 regatta TsL 320 scramble / w in pairs for two (LMH 20, cementmilk grader), pressurized. giving km 250 atm. H | 1dvayte.ppo prgolovi.lp 30 m boers () 1o of a solution of 1750 kg / m p.lotspos. To lower the estuaries1) 1x pressure, lend in tubing jiacTBopa to nanorpal, ect. From (), ti chi () npyye works vypy.lp. Pc in a, pedigree) order.  Zatvor.li and download. N even with a bullet and 1b | gogonic pressure, h (m1ii at the mouth of 1 (), 5 m of cement mortar with a density of 17 () 0 1780 kg / mm for 45 min; all is more expensive than pacco.ia. t.yyuyuyu nemmkogo jiacTBopa remove the last 0 by mt bam 11rime) but at 710. That coo itiei sll (this is the one of the onoppeness l rf b 7.8 m. gp plovi pemeppey 1ashli) paiMccti.las) at that 300 m from the map 11 copies in l shirts: Vlyu.lni.al.yy.le) on / to quMsanne of the centrifugal mortar in a 35 mm bp-mash and prepare for mixing (2 (1 with cement 11111C. Shut down and inject.lp into coarse ni () | iyH) 1I) rtsNK) cement mortar of 17 m p. Density of 1720 kg / m for 35 mpp; prp (lo.m 0 after pumping into tubes1,1 4 5 m UI of the UMIT solution of the second porppy pacha.y; pr () giving, pouring the head part of the nepBoii portions in k (), Lice () e prostrate for burp, pipes, and after pumping) 1I into coarse | 1) () 12 m second by | O. Juvpa Chastica first vsupp, 1a v (l. of grasping; sun, 1b (), lts | O1 o lf) Actual with bore diameter (660 mm) in the inlch dva. Formation of a sealed Gl)) laziness at the end of the injection in the portions portion is not Q noted, hp, but at the end of the pumping of pemengacTBop, place it in the following way: level) of the cement slurry in a depth of about 750 m, osgatok from the nepBoit portions in the pipes m | 14 m ne |) - howling pimples 1and 1sneesi in which, and the development, of which about 5 m entered into (fiu grapple 1) 1 Ekani, B1) P1o.lpp.chp excerpt in lecheppa 10 mpp dl d () s | K vani remnant first nofiiuin in five Due to the complete loss of pumpability of the sol -entonite mixture at the maximum permissible pressure at the wellhead (30 MPa) and complete isolation of the pressure object (as evidenced by the absence of inflow after pressure discharge in the pipes to atmospheric), the further pressure was stopped; -, 9 m left in the pipes. After formation of the jumper and isolation of the pressure object, the hydraulic fracturing zone was discharged, they were convinced that there was no inflow from the pressure object through the annular space, the drill string was removed from the jumper above the jumper with the TDH, the solution diluted with reservoir water with gas and the reservoir water from the annulus were washed space, the density of the solution in the well was increased to 2250 kg / m, connected with the left part of the drill string, and with a pacing it was removed from the jumper. Formula and: Juvent . The method of drilling in conditions of possible brine formations, including separate isolation of areas of possible leaks and pressure object and the descent of the tubing below the bottom of the area of possible leaks, characterized in that, in order to increase efficiency and reduce the total cost of well construction during the overflow from the pressure object under the conditions of unbalanced pressures along the wellbore and subsequent isolation of the pressure object, breaking up the zones of possible leaks and the pressure object is carried out after determination of the fact of forming an airtight separating bridge in the annular space behind the pipes in the trunk section between the pressure object and the area of possible leaks, and work on isolating the pressure object is performed through the pipe channel after separating the pressure object from the area of possible leaks. 2. The method according to claim, characterized in that the formation of a sealed separating jumper is carried out by portion injection of the cement solution into the column of tubes with an exposure to thickening and subsequent displacement of the portions into the annulus under pressure exceeding the pressure in a pressurized object, and the regimes of mixing, pumping and selling, one-turn of the cement slurry is selected in accordance with the following conditions: five 0 where is ti. (t, i + t.11 a t in (I li 1 h in - I Mf) ) I and (n (t.laTB - (- tiipii.l),% T..kTm.agv Tsmrod ,, lOQ-il, - total time from the pack, 1a of the first portion of the gate until the end of the shutter) P1 noc.RMneii, liK. iK) - cha breaks in shutter, min; - the total time from the beginning of mixing the first port to the end of the last setting, including interruptions in mixing and stopping the ripening of the cement slurry up to the stage of filling, .min; 0 ABOUT five 0 five (, .. „+ - (- tripo. I, 5 Tzzg q npo.i Q, rit the total time from the beginning of the mixing of the i-th portion of the cement slurry to the end of the production of the i-th portion to the place of its setting, min; the beginning of the thickening of cement from the time of mixing, min; iCXB is the time it takes for the cement grout to start setting at the moment of closure, .min; - giving cementing units; (flow rate) when displacing the i-th portion of the cement slurry to the point of setting, l / s. - the current flow rate of the inflow from the pressure object before the first pressing of the i-th portion of the cement slurry to the point of setting. i / c. 3. The method according to claim 1, distinguished by the fact that in order to ensure the possibility of extracting pipes from the well noc.ie isolate PNP pressure o6ijeKTa. DJH ((the airtight separating lintel is used to protect the thickener; however, it does not harden when mixed with rasch and black mortar. 4. The method according to p. 3, is distinguished) and (1p 1c with the fact that as thickening, but not hardening when mixed with dissolvine and ourpum cementing smsch N Hcno.ib- solt solvent), the mixture.