SU1222816A1 - Method of drilling holes under conditions of high-head mineralized water manifestations - Google Patents

Description

The invention relates to the construction of deep exploration and production wells for liquid and gaseous minerals.

The aim of the invention is to increase the reliability of well placement and prevent the formation of salt-anhydrite plugs in the drill string.

The drawing shows a diagram explaining the proposed method.

After the drill string 1 is lowered down to the bottom 2, the well is flushed with solution 3 to remove the cuttings and fluid. Buffer 5 is pumped into the fluid entry zone (rap). The wellhead is sealed, for example, with a rotating preventer 6, and drilling is performed. At the same time, the fluid moves from the inlet zone 4 through the annulus 7, downhole 2 into the internal cavity of the drillstring 1 at the mouth When drilling rapore wells, the formation of salt-anhydrite plugs is possible, as well as plugging of the in-line space with cuttings. To prevent this and to remove the cuttings and fluid from the inner cavity of the drill pipe, periodically pumped mud from the surface into the soutube space. During the period of one pumping, the volume of the pumped solution is equal to or slightly exceeds the internal volume of the drill string, which is necessary in order to force the fluid in the internal channel of the drill pipe to the surface.

The frequency of downloads is determined experimentally for each specific case depending on geological, hydrothermodynamic and technological conditions.

To prevent fluid moving with the drilling fluid, after each successive injection, a buffer is pumped into the fluid inlet zone, which can be salty drilling mud or any liquid that is inert to the incoming fluid. Thus, in the well annulus

the solution is divided by the buffer into packs so that after the next periodic injection in the interval of fluid intake (high-pressure mineralized water supply) there is a buffer.

An example of using this method for the conditions of the field Zevar Dy.

In the Zevard deposit, the spreading horizons are confined to the upper layers occurring at a depth of 2200 2400 m.

Well construction is as follows:

426 mm - 5 m direction

324 mm - 100 m extended direction

299 mm - 400 m jig

219 mm - 2700 m technical column

140 mm - 3000 m production column

The drilling in the salt-anhydrite column is carried out with the following configuration, mm: bit 269, drill collar 178, drill string 140.

At the location of the raporious horizon at a depth of 2300 m, the volume of the annulus will be

lm

86 m, inline 25 m.

Therefore, the volume of one periodic flush should slightly exceed 25 m plus the drilled interval below the brine flow.

Buffer fluid is found every 26-27 m of drilling fluid. If it is necessary to increase the volume of one wash, which can be caused by a significant flow of the incoming brine, high penetration rate, the volume of one wash can be doubled, etc. arranging, respectively, the buffer through 50 m solution.

After that, the bit is worked out, the well is rinsed from the calculated-volume of pumped growth, the thief exceeds the double volume of the well, a buffer is pumped into the fluid inlet zone and the tool is lifted to work out the narrowing zones.

In k, as a buffer fluid, it is possible to use emulsion, lime-bit batch i: hydrogel or any salt-resistant drilling mud treated with polymer reagents, etc.

After changing the bit and lowering the drill string, drilling continues

in compliance with all specified technological operations.

When drilling using the proposed method, it is possible to jointly open the halogen and productive strata, accordingly adjusting the density of the drilling fluid and the technological parameters as a whole.

With this method of drilling in the interval of the productive horizon, which is 2228164

The second is located. Significantly below the interval of brine entry (for the Zevardi field, this value is 300-400 m), a drilling fluid with reduced water loss is located. During the period of one dolbylenia, the brine will not have time to reach the productive horizon, since backwash is periodically carried out in order to remove brine and cuttings.

7 Compiled by E.Stolbtsov Editor R.Tsitsika Tehred i.Popovich Proofreader M.Maksimishinets

Order 1682/31 Circulation. 548 Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

Claims (2)

1. WAY OF DRILLING WELLS UNDER THE CONDITIONS OF HIGH-HEAD MINERALIZED WATER MANIFESTATION, including the descent of the drill string with circulation of the formation fluid through the in-pipe space at the wellhead, characterized in that, in order to increase the reliability of the wiring of wells and prevent the formation of drilling and sour water sealing the annulus and periodically carry out the injection of drilling fluid into the annulus according to the reverse circulation scheme until the crowds are completely displaced ovogo fluid from the cavity of drill pipes on the surface, wherein the injection period is less than the time of formation hydrochloride anhydrite plugs. 2. The method according to claim 1, characterized in that after the next periodic injection into the intake zone, the buffer fluid is pumped into the fluid. the solution is divided into packs with the buffer so that after the next periodic injection, a buffer is located in the interval of fluid intake (high-pressure mineralized water development). An example of the use of this method for the conditions of the Zevardi field. Yu. At the Zevardy deposit, the developing horizons are confined to the upper layers, which lie at a depth of 22002400 m. Well design is as follows: 426 mm -5 m direction 324 mm - 100 m elongated direction 299 mm - 400 m conductor 219 mm - 2700 m technical column 140 mm - 3000 m production casing Drilling along the salt-anhydrite stratum is carried out by the following arrangement, mm: bit 269, drill collar 178, drill string 140. With the location of the developing horizon at a depth of 2300 m, the volume of the annulus will be 86 m. Of the inner tube 25 m. Therefore, the volume of one periodic washing should slightly exceed 25 m ³ plus the drilled interval below brine. Every 26-27 m ^{3 of} drilling fluid contains buffer fluid. If it is necessary to increase the volume of one washing, which can be caused by a significant flow rate of the incoming brine, a high penetration rate, the volume of one washing can be doubled, etc. placing respectively a buffer through 50 m ^{3 of} solution. After that, the bit is worked out, the well is flushed based on the calculation — the volume of the pumped solution exceeds the double volume of the well, the buffer is pumped into the fluid supply zone and the tool is lifted with the narrowing zones worked out. As a buffer fluid, you can use emulsion, lime-bitumen 1, hydrogel or any salt-resistant drilling fluid treated with polymer reagents, etc. After changing the bit and lowering the drill string, drilling continues