RU2694317C1 - Method of completion and development of steam horizontal wells producing high-viscosity oil - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil-producing industry. Method for completion and development of steam horizontal wells producing high-viscosity oil includes construction of horizontal production well and injection well located above and parallel to production well, creation of permeable zone between wells due to delivery of heat carrier to both wells. After creating the permeable zone, steam is supplied only to the injection well, and production is selected from the production well. Horizontal production well during construction is equipped with fiber-optic cable with temperature sensors, and for creation of permeable zone to productive formation through both wells heat carrier is supplied with temperature of not less than 90 °C, but not higher than evaporation temperature in formation conditions, and pressure, which enables hydraulic fracturing of formation, but not higher than pressure of formation reservoir cover rupture, for 1 to 3 days. Then, steam is injected for injection of at least 4 t per running meter of horizontal wellbore of each well with further stopping for thermocapillary impregnation. At that, in the horizontal wellbore of the production well there performed are geophysical studies for detection of transition zones between larger and smaller heating, in which zone with change of angle of set of curvature of not more than 2 degrees per 10 m is selected for arrangement of the pump input lowered on the tubing string and equipped with pressure and temperature sensors at the inlet. Pumping of steam through injection well is resumed, and product extraction is performed by pump with thermogram removal along production well shaft and temperature measurement at pump intake. When the liquid temperature drops below the maximum permissible value at the pump inlet steam injection through the injector is increased. As the temperature increases at the pump inlet, steam injection through injection well is reduced and/or the pump is switched to periodic operation mode. After temperature stabilization at the level of maximum permissible pump is changed to normal operation mode.

EFFECT: faster development of wells, elimination of uneven heating and steam breakthrough to production well, higher reliability of operation, reduced power and material costs.

1 cl, 3 dwg, 1 ex

Description

The invention relates to the oil industry and can find application in the development of deposits of highly viscous and bituminous oil.

There is a method of developing a field of heavy oil or bitumen using two-well horizontal wells (patent RU No. 2340768, IPC Е21В 43/24, publ. Byul. No. 34 dated 12/10/2008), including the injection of coolant through a two-well horizontal injection well, warming up the productive formation the creation of a steam chamber and the selection of products through a two-well horizontal production well, while heating the reservoir begins with the injection of steam into both wells, warm up the interborehole zone of the reservoir, reduce oil viscosity or bitumen, and the steam chamber is created by injecting coolant with the possibility of piercing the latter to the upper part of the productive formation and increasing the size of the steam chamber during the product selection process, in which thermograms of the steam chamber are removed, analyze its warm-up condition for uniform heating and the presence of temperature peaks, and taking into account thermograms carry out a uniform heating of the steam chamber by changing the direction of filtration and / or the modes of injection of the coolant and the selection of products, while the injection volume is warm ositelya through the mouth of the injection well and / or selection of products through the mouth of the production well at a ratio change,%: (10-90) :( 90-10).

The disadvantage of this method is the high material and energy costs for the construction of two-hole horizontal wells associated with the need for drilling, planting, cementing and arranging the second mouth. During the development of steam injection steam requires considerable time and volume of the injected agent to create a steam chamber and its distribution throughout the interval of the horizontal wellbore, the process is accelerated during the initial horizontal hydraulic fracturing.

There is a method of developing deposits of high-viscosity oil and bitumen (patent RU No. 2597303, IPC Е21В 43/247, publ. Byul. No. 25 of September 10, 2016), which includes drilling of deposits with two technological wells and a production well with horizontal shafts, installation in horizontal trunks of technological electrode wells, connecting electrodes to an electrical substation at the wellhead, lowering the horizontal centrifugal pump to the horizontal wellbore of the production well, warming up the deposit with electric current using those installed in the horizontal barrels of cnologic wells of electrodes, selection of heated oil and bitumen from a deposit by an electric centrifugal pump from a horizontal wellbore of a producing well, characterized in that initially at least one producing well and one heating well are drilled with horizontal trunks arranged in parallel and under each other at a distance of 15 m, then the upper horizontal wellbore of the heating well produces a hydraulic fracturing with the formation of a longitudinal crack with its subsequent fastening with a conductive material, then, perpendicular to the initial section of the horizontal wellbore of the heating well, the first technological well with the horizontal wellbore is drilled, and perpendicular to the end section of the horizontal wellbore of the heating well, the second technological well with the horizontal wellbore is drilled, and the horizontal trunks of the technological wells are placed within the fractures of the hydraulic fracturing, parallel to the technological wells their vertical trunks and perpendicular horizontal trunks heating and production wells; two additional production wells are drilled; horizontal trunks of additional production wells by electric centrifugal pumps, carry out heating of the reservoir with the help of upper horiz ntalnogo barrel heater wells, and the selection of the heated oil and bitumen is carried out using electrical submersible pump via the lower horizontal wellbore of the production well and the horizontal production wells additional trunks.

The disadvantages of the method are: significant costs for drilling production of horizontal and technological vertical wells, as well as additional horizontal wells; large energy losses for the implementation of the electric heating of the reservoir compared with the injection of coolant, the risk of not creating a thermo-hydrodynamic connection between the heating and lower production wells, due to the fair distance of 15 m between the wells.

There is also known a method for developing a deposit of super-viscous oil (patent RU No. 2531412, IPC E21V 43/24, publ. Byul. No. 29 dated 10/20/2014), which includes drilling a pair of horizontal upper injection and lower production wells, the horizontal sections of which are parallel to each other in the vertical plane, heating the reservoir by injecting steam into both wells with the formation of a steam chamber, heating up the interborehole zone of the reservoir, reducing the viscosity of super-viscous oil, injecting steam into the upper horizontal injection well and selecting products from the lower mountains izontalnoye producing wells, while the reservoir is heated by steam injection into both wells until the value of the steam-oil ratio is stabilized, after which three modes of development of a super-viscous oil field are used alternately, the first mode includes steam injection into the injection well and holding it in the reservoir for 48-72 hours, the second mode includes the injection of propylene glycol into the producing well at the rate of 5 m per 100 m of the horizontal section of the producing well with the content of the main substance not less than 98% with a holding in the reservoir for 12-24 hours s and simultaneous circulation of water vapor in the injection well, the third mode includes the production of high-viscosity oil from the production well before the steam-oil ratio increases 1.5 times.

The disadvantages of the method are the lack of control of uniformity of heating of the interwell well space at all stages of operation of a pair of wells, which can lead to steam breakthroughs and failure of pumping equipment. Also, after the start of the production selection of the production well and the achievement of the paro-oil ratio of 2.2-3.8 m ³ / t, that is, the actual production of a growing oil production rate, it is impractical to stop the selection, transfer a couple of wells to a cyclic mode of operation, including a period of 48-72 days without steam injection, which will lead to the evaporation of the steam chamber and the need to re-develop the steam of both wells and create a steam chamber.

The closest to the claimed method for the combination of essential features is a method for developing an oil-bitumen deposit (patent RU No. 2287677, IPC Е21В 43/24, publ. Byul. No. 32 of November 20, 2006), including the construction of a producing two-well horizontal well and product selection, above the producing two-well horizontal well parallel to it build an injection two-drain horizontal well, create a permeable zone between the wells due to the injection of water vapor into both wells, after creating the permeable zone under steam is pumped only into a two-well horizontal injection well, and production is taken from a producing two-vent horizontal well, the degree of dryness of the injected steam is alternated periodically, first steam is pumped to a high degree of dryness until the injection wells of the two-hole horizontal well and the fraction of steam in the extracted product are injected, and then pairs of low degree of dryness, the volume of which is determined by increasing the discharge pressure, which is maintained not exceeding the opening pressure vertical fractures, and products are taken from a producing two-well horizontal well until full production is completed.

The disadvantages of this method are the high material and energy costs for the construction of two-hole horizontal wells associated with the need for drilling, planting, cementing and arranging the second mouth, during the development of steam injection requires considerable time and volume of the injected agent to create a steam chamber and its distribution throughout the interval horizontal wellbore, the process is accelerated during the initial horizontal fracturing. There is also no monitoring of the state of heating of the horizontal well of the production well, which can lead to steam breakthroughs to the pump and to uneven heating, and the use of a swab pump that has several disadvantages (low productivity, high wear of the swab and rubber seals, the need for finding the lift and the underground repair team at the mouth of the producing well).

Technical objectives of the proposed method are to reduce material and energy costs, accelerate the development of wells due to injection in the initial period of development of the coolant - hot water at a pressure of injection sufficient to create horizontal cracks, accelerating further development of the well with steam, eliminating uneven heating and breaking the steam into the producing well through the use of warm-up control, and an increase in reliability due to the use of submersible pumps installed at the most technologically advanced Ski reasonable places.

Technical problems are solved by the method of development and development of paired horizontal wells producing high-viscosity oil, including the construction of a horizontal production well and an injection well, located above and parallel to the production well, creating a permeable zone between the wells by injecting coolant into both wells, and after creating the permeable zone the steam is only in the injection well, and the production well is taken from the production well.

New is that a horizontal production well during construction is equipped with an optical fiber cable with temperature sensors, and to create a permeable zone, coolant is supplied through both wells with a temperature of at least 90 ° C, but not higher than the vaporization temperature in reservoir conditions, and allowing pressure to be produced hydraulic fracturing, but not higher than the burst pressure of the tire of the productive formation, from 1 to 3 days, after which they go under steam injection before pumping at least 4 tons per horizontal meter ntalnogo wellbore of each well, followed by stopping for thermocapillary impregnation, while in the horizontal well of the production well carry out geophysical studies to identify transition zones between larger and smaller heating in which choose a zone with a change in the angle of curvature of not more than 2 degrees at 10 m to accommodate the entrance a pump running on the tubing string - tubing and equipped with pressure and temperature sensors at the inlet, then steam injection through the injection well is resumed, and the extraction of steam Pumping is done with thermogram removal along the wellbore well and measuring the temperature at the pump intake, when the fluid temperature drops below the maximum allowed at the pump inlet, steam injection through the injection well is increased, and when the temperature at the pump inlet decreases, steam injection through the injection well and / or transfer the pump to a periodic mode of operation, after stabilization of the temperature at the level of the maximum allowable, the pump translate normal operation.

FIG. 1 shows a diagram of horizontal wells in the reservoir during injection.

FIG. 2 shows a diagram of horizontal wells in the reservoir during sampling.

FIG. 3 shows a water-steam transition diagram as a function of temperature and pressure.

The method of development and development of paired horizontal wells producing highly viscous oil includes the construction in the reservoir 1 (Fig. 1, 2) of horizontal single-well production wells 2 and an injection well 3 located above and parallel to the producing well 2. Horizontal production wells 2 are equipped during construction fiber optic cable with temperature sensors. A permeable zone is created between wells 2 and 3 by injecting coolant into both wells 2 and 3. After the permeable zone is created, steam is supplied only to the horizontal injection well 3, and production 4 is extracted from the horizontal well 2 (Fig. 2). To create a permeable zone in both wells 2 (Fig. 1) and 3, two tubing columns are placed — tubing 5 and 6 (in the production well 2 with a filter part less than 700 meters, one tubing 5 is placed — not shown). The creation of a permeable zone between wells 2 and 3 is carried out by pumping water at a temperature of at least 90 ° C, but not higher than the vaporization temperature under reservoir conditions (see Fig. 3), and pressure, which allows hydraulic fracturing, but not higher than the rupture pressure of the tire productive layer, for 1 to 3 days:

P = Rust + Pgs,

where P is the bottomhole pressure, atm;

Rust - injection pressure at the wellhead 2, 3, atm

Pgs - hydrostatic pressure of a liquid column, atm;

Rust = H * k

where H is the depth of the roof of the sand pack, m;

k - coefficient for conditions of shallow layers - 0.2;

When this occurs, hydraulic fracturing occurs, cracks 7 are created and develop in the horizontal plane, since for shallow reservoirs 1 (up to a depth of 400 meters) the passive pressure of the soil significantly exceeds the rock pressure, this is the tectonic overrun mode, when the rock pressure is the minimum main stress, while the burst pressure is almost equal to the rock pressure, slightly exceeding it, while not breaking the tire of the reservoir.

Next, steam injection continues (Fig. 3) into wells 2 (Fig. 1) and 3 until injection of at least 4 tons per linear meter of horizontal well bore 2 and 3. Next, wells 2 and 3 are stopped for holding for thermocapillary impregnation and cooling of the extractive stem wells 2, in which thermobarometric measurements are carried out by means of geophysical studies, the results of which reveal transition zones (not shown in the horizontal well of production well 2) with a temperature between higher and lower heat in the horizontal wellbore of the production well 2. Among the identified zones, a zone with a change in the angle of curvature set of no more than 2 degrees per 10 m is defined, in which the pump 4 inlet (Fig. 2) is lowered onto the tubing string 8 and equipped with pressure and temperature sensors (not shown) at the inlet. Steam injection through the injection well 3 is resumed, and product 4 is sampled with a thermogram removed along the wellbore of the production well 2 via a fiber-optic cable and temperature measured at the pump inlet 4, if present, to monitor the process of uniform heating of the production well 2. As the fluid temperature drops below maximum permissible at the inlet of the pump 4 (determined by the manufacturer) increase the steam injection through the injection well 3, and with increasing temperature at the inlet of the pump 4 decreases by steam injection through the injection well 3 and / or translate the pump 4 in the periodic mode. After stabilization of the temperature at the inlet of the pump 4 is equal to the maximum permissible under the conditions of operation of the pump 4 transfer normal operation.

An example of a specific implementation.

In reservoir 1 (Fig. 1 and 2), the viscosity of the oil is 27350 * 10 ^-6 m ² / s (at 8 ° C). The field produces construction of a pair of horizontal wells 2 and 3. A production well 2 with a horizontal barrel 827 m long at a depth of 95 m was drilled with a chisel 244.5 mm in diameter and lined with a column with slits - a slotted filter (not shown) with an optical fiber cable equipped with temperature sensors . The injection well 3 with a horizontal barrel 823 m long at a depth of 90 m was drilled with a chisel with a diameter of 244.5 mm. The horizontal wellbore 3 is surrounded by a column with slits - a slit filter (not shown). In the horizontal barrel of the injection well 3 (Fig. 1) two tubing columns are placed — tubing 5, the end of the first tubing tubing 5 with a diameter of 60 mm to a depth of 230 m, and the end of the second tubing tubing 5 with a diameter of 89 mm are lowered into the second half of the horizontal wellbore a depth of 635 m. In the production well 2, the end of the first tubing string 6 with a diameter of 60 mm is lowered to a depth of 320 m, the end of the second tubing string 6 with a diameter of 89 mm is lowered into the second half of the horizontal wellbore to a depth of 753 m. Next, steam is pumped in for 52 hours with pressure download at the mouth - 1 8 atm for injection well 3 and 19 atm for extractive 2 to create cracks 7. This steam, being cooled in the trunk of a cold well, is condensed into water. Then continue pumping dry steam with a volume of 5300 tons to the producing well 2 and 5,600 tons to the injection well 3, the steam does not condense in the heated well, after the injection of this volume of steam ends, wells 2 and 3 stop for aging for thermocapillary impregnation and cooling of the well stem 2 in which, after extraction of two columns of tubing 6, thermobarometric measurements are carried out by means of geophysical studies, according to the results of which transition zones with temperature are detected in the horizontal wellbore of the production well 2 between the larger and smaller warm-ups, and among the identified zones, a zone with a change in the angle of curvature set is not more than 2 degrees per 10 m, in which the centrifugal pump 4 of the ETSN5A-160-300 grade equipped with on reception by temperature and pressure sensors. Information from sensors is transmitted via cable to the wellhead 2.

Pumped steam through injection well 3 in the amount of 160 tons / day and select formation products by means of electric centrifugal pump 4 through production well 2. Thermograms are taken along the barrel of production well 2 and temperature and pressure are measured at the inlet of electric centrifugal pump 4.

The permissible temperature at the reception of this centrifugal pump 4 is 128.6 ° C. The temperature at the intake of the electric centrifugal pump 4 is 112.9 ° C. At this temperature, operate the pump 4 in a constant mode. Increase steam injection through injection well 3 by 15%.

When the temperature in the area of the electric centrifugal pump is more than 128.6 ° C, the pump 4 is transferred to the periodic mode of operation 80/20 (80 minutes of operation / 20 minutes of inactivity, etc.) and the steam injection in the injection well 3 is reduced by 10%.

When the temperature at the inlet of the electric centrifugal pump 4 is close, but not more than 128.6 ° C, the pump 4 is transferred to a constant - the normal selection mode, which allows to maintain the specified temperature for the maximum possible period of time (determined empirically).

Compared with the neighboring wells, deposits that were initially mastered by injecting only dry steam, heating of production well 2 turned out to be higher by 25 ° C according to the results of geophysical studies, and the rate of appearance of oil in production of production well 2 after the start of extraction is 18 days earlier. Due to the constant monitoring of the thermograms in the production well 2, not a single steam breakthrough was recorded. The uniformity of heating over the entire length of the production well 2 is maintained by using two tubing tubing 4 of different diameters in the injection well 3. The use of a submersible electrocentrifugal pump 4 made it possible to increase the selection by 70% of the production by increasing the time of trouble-free operation threefold.

The proposed method of development and development of paired horizontal wells producing highly viscous oil allows reducing material and energy costs and speeding up the development of wells due to the injection of hot water at the initial period of development of the heat carrier at an injection pressure sufficient to create horizontal cracks, eliminating unevenness warming and breaking steam into the production well through the use of warm-up control, and increasing the reliability of operation by using submersible pumps installed in the most technologically sound places.

Claims (1)

The method of development and development of paired horizontal wells producing high-viscosity oil, including the construction of a horizontal production well and an injection well, located above and parallel to the production well, creating a permeable zone between the wells by injecting coolant into both wells, and after creating the permeable zone only steam is supplied injection well, and production is taken from the production well, characterized in that the horizontal production well during the construction t fiber-optic cable with temperature sensors, and to create a permeable zone, a coolant with a temperature of at least 90 ° C, but not higher than the vaporization temperature under reservoir conditions, and pressure, which does not exceed pressure, is fed into the reservoir through both wells. rupture of the tire of the productive formation, for 1 to 3 days, after which they go under steam injection to pump at least 4 tons per linear meter of the horizontal wellbore of each well, followed by stopping to thermocapillary pits, while in the horizontal well of the production well, geophysical studies are carried out to identify transition zones between higher and lower heat, in which a zone with a change in the angle of curvature not exceeding 2 degrees by 10 m is selected to accommodate the pump inlet descending on the tubing string The tubing and equipped with pressure sensors and inlet temperatures, then steam injection through the injection well is resumed, and pump selection is performed with removal of the thermogram along the barrel of the production well and With a temperature at the pump intake, when the fluid temperature drops below the maximum allowed at the pump inlet, steam injection through the injection well is increased, and as the pump inlet temperature rises, steam injection through the injection well is reduced and / or the pump is switched to a periodic operation mode, after the temperature has stabilized the level of the maximum allowable pump is transferred to normal operation.

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