Fluid for plugging wells drilled with the opening of a productive layer in the depression, and the method of killing a well drilled with the opening of a productive layer in the depression (and its variants)

 

The invention relates to the field of well drilling and oil production, in particular, to a method of killing a well drilled with the opening of a productive layer in the depression, and can be used, for example, before conducting geophysical research before lowering the downhole equipment, etc., the Technical result - the complete preservation of reservoir properties of productive formation while killing the well, drilled with the opening of a productive layer in the depression, while increasing intensification of the flow of formation fluids during the development of such wells. The use of a by-product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes as well kill fluid wells drilled with the opening of a productive layer in the depression. In the process of killing wells drilled with the opening of a productive layer in the depression, have pumped into the borehole fluid damping is a by - product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement fluid damping to vyravnivatelyami the displacement produced crude oil, which made the opening of the productive formation by drilling, and then raise the drill pipe to roof packs of kill fluid and produce fill the remaining wells of the same oil to natural static level. You can produce a displacement of the kill fluid to equalize its level in the pipe and annulus, with equal hydrostatic pressure in the well and reservoir pressure the displacement produce heavy oil with a density of more than 0.90 g/cm³after which raise the drill pipe to the upper limit of bundles kill fluid and produce fill the remaining wells of the same oil. You can produce a displacement of the kill fluid to equalize its level in the pipe and annulus, above reservoir pressure above the hydrostatic pressure in the borehole the displacement produce a bundle of invert emulsion to the extent that the filling of the wellbore above the liquid level killing not less than 50 m, and then raise the drill pipe to roof packs invert emulsion and produce fill the remaining wells with wash liquid of the estimated density. As invert EMU is th water,=1,17 g/cm³69,1-77,2, emulsifier "Urinal 1" or its facilities at the Moscow-354 0,4, Smad-1 3,8-3,9, bentonite is 0.5. As drilling fluid use produced water estimated density. 4 S. and 2 C.p. f-crystals, 1 table.

The invention relates to the field of well drilling and oil production, in particular to a method of killing a well drilled with the opening of a productive layer in the depression, and can be used, for example, before conducting geophysical research before lowering the downhole equipment, etc.,

It is known the use of a by-product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes in combination with an emulsifier as a reagent for invert emulsion drilling fluids (1).

Also known application of a by-product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes in combination with magnesium chloride, acetylcellulose and water as a base fluid for separation of wash and perforating fluids (2).

There is also known a method of plugging wells, according to which have pumped into the well kill fluid is an aqueous solution of polyethylene oxide, to the extent that the filling of the barrel schwag for the deposition of kill fluids at the well bottom, and the remaining hole is filled with an aqueous solution of mineral salts with the speed of leveling is not more than 1 m/s (3).

However, this known method does not provide full preservation of reservoir properties of productive formation. This is because getting into the producing formation of polyethylene oxide does not exclude the effect of "permeability", as the collector is not released from the aqueous filtrate.

A single technical result achieved in the implementation of the claimed group of inventions is the complete preservation of reservoir properties of productive formation while killing the well, drilled with the opening of a productive layer in the depression, while increasing intensification of the flow of formation fluids during the development of such wells.

This technical result is achieved by the fact that as well kill fluid wells drilled with the opening of a productive layer in the depression, it is suggested to use a byproduct of the production of synthetic rubber at the stage of obtaining dimethyldioxanes (hereinafter referred to as T-92).

Flotation T-92 is a byproduct of the production of dimethyldioxanes and is an oily one - 2 Sum of x dopisannogo alcohol - 9,5 Peranovic alcohol - 4 Sum x iodixanol alcohol - 15 Sum x methylbutanol - 1.5 Sum x dioxane alcohols - 50 the Amount of heavy residue - 18 Essential T-92 is 1.5-4 mg KOH/g; the mass fraction of hydroxyl groups 23-36%; flash T-92 in an open crucible +90^oWith the freezing temperature of minus 50^oC.

When getting offered the kill fluid into the zone of the productive interval of the formation occurs, apparently, two processes: the process of binding the residual water in the reservoir, and the partial surfaces of the collector mixture of higher alcohols, and are excluded as the clogging of the pores of the reservoir, and the effect of "permeability", which means the primary reservoir properties are not only preserved and even improved.

In the course of the above processes occurring in the reservoir under the influence of T-92, creates favorable conditions for the promotion of oil development wells, i.e., stimulating the flow of oil from the reservoir.

This technical result is also achieved by a method of killing a well drilled with the opening of a productive layer in the depression, on the first of variola synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement of the kill fluid to equalize its level in the pipe and annulus, when exceeding the hydrostatic pressure in the well above the formation displacement produces crude oil, which was carried out the autopsy of the productive formation by drilling, and then raise the drill pipe to roof packs of kill fluid and produce fill the remaining wells of the same oil to natural static level; according to the second variant, characterized in that what have pumped into the borehole fluid damping is a by - product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement of the kill fluid to equalize its level in the pipe and annulus, with equal hydrostatic pressure in the well and reservoir pressure the displacement produce heavy oil with a density of more than 0.90 g/cm³after which raise the drill pipe to Verhaegen option harakteryzuyetsya fact, what have pumped into the borehole fluid damping is a by - product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement of the kill fluid to equalize its level in the pipe and annulus, above reservoir pressure above the hydrostatic pressure in the borehole the displacement produce a bundle of invert emulsion to the extent that the filling of the wellbore above the liquid level killing not less than 50 m, then raise the drill pipe to roof packs invert emulsion and produce fill the remaining wells with wash liquid of the estimated density.

As an invert emulsion in the method according to the third variant predominantly use an emulsion of the following composition, wt.%: Diesel summer - 18,1-26,1
Mineralized formation Water,=1,17 g/cm³- 69,1-77,2
Emulsifier "Urinal 1" or its facilities at the Moscow-354 - 0,4
Smad-1 - 3,8-3,9
Bentonite - 0,5
and as a flushing fluid use produced water estimated density.

Lagerware productive formation is at a height of not less than 100 m, provides guaranteed preventing fluid produce in the area of the reservoir even at different speeds, the injection of this fluid.

Use as liquid produce in the first embodiment of crude oil, which made the opening of the reservoir, allows to achieve the level in the pipe and annulus without a strong push of a productive formation fluid damping, because crude oil is usually light or medium oil.

The second option, use as liquid produce heavy oil with a density of more than 0.9 g/cm³allows you to create a soft effect produce to align the pipe and annulus level without a strong push of a productive formation fluid damping, the same effect is created and by the third variant by produce invert emulsion, which has a density 1,04-1,15 g/cm³but fill this invert emulsion also the wellbore to a height of not less than 50 meters

Due to such varying types of liquid produce depending on the ratio of hydrostatic and pressure is ensured guaranteed exception zadavki the kill fluid in productive PLA is in all three variants to the upper limit of bundles kill fluid provides a reliable substitution of oil in the well kill fluid. The ascent of the kill fluid in the first and second embodiments is eliminated due to the higher density fluid damping in comparison with the density of the oil, fill the rest of the wellbore. In the third embodiment, the ascent of kill fluids are prevented by the use of invert (reverse) the emulsion of high viscosity to a state of "not flowing") and with high structural-mechanical characteristics of Q_1/10=10/12.

Filling the remaining volume of the well fluid produce provides for the establishment of equilibrium conditions between hydrostatic and formation pressures.

In this application complied with the requirement of unity of invention as claimed kill fluid and all variants of the process of killing the well through the kill fluid constitute a single inventive concept and, together, they solve the same task, complete elimination of clogging of the productive formation and increase the stimulation of oil development wells.

We offer you kill fluid was tested in the laboratory to establish its impact on the reduction of permeability of core samples. The research was carried out as follows.

The formation of zones of sedimentation and prontohotel permeability was studied on samples of rocks bobrikovsky deposits Envisage field. Studied a range of problematic collectors with hard to recover reserves.

The experimental procedure included the preparation of sample collections (selection, extraction, drying, saturation model produced water with a salinity of 234 g/l NaCl). Next, the method of semi-permeable membrane was created residual water saturation. Then were Considine hydrocarbon phase (kerosene) under vacuum. For each sample in terms of the approximate simulation of the occurrence of productive breeds was determined permeability to kerosene in the presence of residual water (CPRC 1, table). In all experiments was maintained the same consumption of kerosene, was strictly controlled by the effective pressure (7 MPa), the filtering and temperature.

The next step was the simulation of the near-well zone, and on the borehole wall" - the output end of the composite model were breed with a maximum permeability (arr. 53947 table) and away from "well" permeability decreased. First was determined permeability model for kerosene, which in the first hour of its loading effective pressure of 7 MPa was 29 x 10^-3μm²then one day exposure decreased to 19.2 x 10^-3μm². Pozravlenie investigated liquid damping was created differential pressure (Rscw-CL =0.5 MPa), which was supported by the day. "Development well" was carried out by filtering of the reservoir. When the differential pressure of 0.5 MPa in the first minutes of the filter does not exist, then quickly she began to grow. Half an hour later the rate of increase of permeability sharply decreased after 2 hours and 15 minutes permeability was compared with the original and then stabilized at about 20.210^-3μm². Only one sample recovery coefficient of permeability (KVP) was 76.4%, the rest is much higher. In the sample 53961 with the complex structure of the first space (the maximum content of residual water 21%) recovery coefficient of permeability was of 160.4%.

The average recovery factor of permeability for all samples was 105,9% (see table) and almost equal in magnitude KVP composite model, equal of 105.2%.

Thus, the application of the proposed well kill fluid prospectively for killing wells drilled on depression, including wells that discover low permeability reservoir, as this not only breaks the clogging area and penetration, but even increases the permeability of privatenotespage proposed fluid damping.

Thus, from the above data it is obvious that killing the well proposed well kill fluid is combined with the stimulation.

The proposed method of killing a well drilled on depression, is based on the following technologies. Under the first option: for geophysical research required to plug the well 655 Shumovskii field drilled with the opening of a productive layer in the depression, with the following characteristics:
drilling depth 1400 m;
the reservoir is verey horizon;
hydrostatic pressure above reservoir pressure;
static level when operating at a depth of 500 m

Using cementing unit CA-320M, well pump 1.4 m³the kill fluid T-92, filling this volume of the productive interval of the formation and the wellbore 100 m above the roof of this layer.

Then, using crude oil density 0,86 g/cm³(light type of oil), which was used for the drilling of this well, punching kill fluid to establish equilibrium in the pipe and annulus. Further up the drill pipe to 1290 m - upper bound tutu fluid Glusha what I 500 m Then lowered into the borehole geophysical instruments for recording the Republic of Kazakhstan.

For the second variant (with equal hydrostatic and pressure) technology implementation was similar to the above, except that, as the fluid produce used heavy oil with a density of more than 0.9 g/cm³.

By the third variant (when formation pressure exceeds the hydrostatic) as liquid produce used invert (reverse) the emulsion, for example, the following composition, wt. %: diesel summer 18,1-26, 1; mineralized formation water (= 1,17 g/cm³) 69,1-77,2; emulsifier "Urinal 1 (on THE 38101197-74) or its facilities at the Moscow-354 (TU 38125237-85) 0,4; Smad-1 (TU 38-1-10-65) of 3.8-3.9 and bentonite (GOST 25795-83) of 0.5.

This invert emulsion was set equal levels of kill fluid in the pipe and the annulus filled her wellbore to a height of not less than 50 m above the upper liquid level of the mute and after lifting drill pipe she poured the rest of the wellbore.

In all three embodiments, when lifting the drill pipe produced refilling the well fluid produce, and, in the first embodiment to the static level and the second and third options to the mouth of the 0, from 1989

3. RF patent 2123580, CL E 21 In 43/12, 1998

Claims

1. The use of a by-product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes as well kill fluid wells drilled with the opening of a productive layer in the depression.

2. The method of killing a well drilled with the opening of a productive layer in the depression, characterized in that have pumped into the borehole fluid damping is a by - product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement of the kill fluid to equalize its level in the pipe and annulus, when exceeding the hydrostatic pressure in the well above the formation displacement produces crude oil, which was carried out the autopsy of the productive formation drilling, then raise the drill pipe to roof packs of kill fluid and produce fill the remaining wells of the same oil to natural static level.

3. The process of killing the well, the sample is inu well kill fluid - a by-product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement of the kill fluid to equalize its level in the pipe and annulus, with equal hydrostatic pressure in the well and reservoir pressure the displacement produce heavy oil with a density of more than 0.90 g/cm³after which raise the drill pipe to the upper limit of bundles kill fluid and produce fill the remaining wells of the same oil.

4. The method of killing a well drilled with the opening of a productive layer in the depression, characterized in that have pumped into the borehole fluid damping is a by - product of the production of synthetic rubber at the stage of obtaining dimethyldioxanes, to the extent that the filling of the wellbore above the roof of the productive interval of the formation to a height of not less than 100 m, and then produce a displacement of the kill fluid to equalize its level in the pipe and annulus, above reservoir pressure above the hydrostatic pressure in the well of projecti killing not less than 50 m, then raise the drill pipe to roof packs invert emulsion and produce fill the remaining wells with wash liquid of the estimated density.

5. The method according to p. 4, characterized in that as an invert emulsion using emulsion of the following composition, wt.%:
Diesel summer - 18,1-26,1
Mineralized formation water,=1,17 g/cm³- 69,1-77,2
Emulsifier "Urinal 1" or its facilities at the Moscow-354 - 0,4
Smad-1 - 3,8-3,9
Bentonite - 0,5
6. The method according to p. 4, characterized in that as the drilling fluid use produced water estimated density.