RU2373384C1 - Method of thermal impact at deposit of highly viscous oil and bitumen - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention is related to development of oil deposits, in particular to methods of thermal impact at deposit containing highly viscous oil. Method includes drilling of horizontal injection wells, drilling of producing horizontal well under each injection well within the limits of the same productive bed for bleeding of highly viscous oil and bitumen, pumping of coolant into horizontal wells. Rows of vertical production wells are drilled for extraction of highly viscous oil and bitumen. Between rows of vertical production wells within the limits of productive bed they drill rows of above mentioned horizontal wells. Highly viscous oil and bitumen are extracted from horizontal productive wells until coolant breaks through into vertical productive wells from horizontal injection wells. Afterwards coolant pumping into horizontal injection wells is stopped, and they are changed over to production wells, and horizontal production wells are changed to injection wells. Further when coolant breaks through from horizontal injection wells that were changed over earlier from production wells into vertical production wells, a reverse change over is done from horizontal injection wells into production wells, and horizontal production wells are changed into injection wells, and so the cycle is repeated until bed is exhausted.

EFFECT: increased thermal coverage of deposit.

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Description

The invention relates to the development of oil fields, in particular to methods of thermal exposure of a reservoir containing highly viscous oil.

The well-known "Method of thermal impact on a reservoir of highly viscous oil and bitumen" (patent RU No. 2287677, ЕВВ 43/24, published in Bull. No. 7 of November 20, 2006), including drilling a horizontal well, drilling an additional horizontal well under a horizontal well within the same reservoir, injection of coolant into horizontal wells, production of high-viscosity oil and bitumen by a lower horizontal well.

The disadvantage of this method is the inefficiency of its application, associated with both additional costs for drilling an additional well, and with a small coverage of the thermal effects of the reservoir.

The closest in technical essence is the "Method of thermal exposure of a highly viscous oil reservoir" (patent RU No. 2199656, ЕВВ 43/24, published in Bul. No. 6 of 02.27.2003), including drilling a series of vertical injection and production wells, drilling horizontal wells along rows of vertical wells, periodically injecting coolant, such as steam, into horizontal wells and taking oil from vertical production wells, while also taking from vertical injection wells, and during the period of termination of steam injection, selection of horizontal wells, are a source of vapor breakthrough in vertical wells, and after making the formation near bottomhole zone of the wells are transferred to areal injection displacing agent such as water, into the vertical injection wells simultaneously selecting the remaining oil from the wells.

The disadvantages of this method are:

- low coverage of the sections of the formation by thermal influence (one row of a horizontal well) and, as a result, low coverage and oil recovery coefficients of the highly viscous oil deposit, rapid flooding of the reservoir due to cooling of the coolant and reservoir formation;

- there is no provision for the transfer of vertical production wells to vertical injection wells for pumping coolant while reducing the flow rate of the reservoir:

- low rates of oil bitumen extraction, since this method does not provide for a second row of horizontal wells and the translation of horizontal production wells into injection wells and vice versa.

The objective of the invention is the additional involvement in the development of sections of deposits of highly viscous oil and bitumen, that is, increasing the coverage of the thermal effect of the reservoir by adding movement of the filtration fluid flows in it and, as a result, increasing the coverage and oil recovery coefficients of the reservoir due to the construction of a number of additional horizontal wells and translation horizontal production wells to horizontal injection wells, as well as an increase in the production of oil bitumen reserves due to the transfer of vertical producing wells in vertical injection wells to pump coolant.

The problem is solved by the method of thermal impact on a reservoir of highly viscous oil and bitumen, including drilling horizontal injection wells, drilling a horizontal production well under each injection well within the same reservoir to select high viscosity oil and bitumen, pumping coolant into horizontal wells.

What is new is that rows of vertical production wells are drilled for the extraction of highly viscous oil and bitumen, rows of the above horizontal wells are drilled between the rows of vertical production wells within the reservoir, high viscosity oil and bitumen are taken from horizontal production wells before the coolant breaks into the vertical production wells from horizontal injection wells, after which the coolant is not pumped into horizontal injection wells and transferred to production wells, and g horizontal production wells - to injection wells, then, when the coolant breaks out from horizontal injection wells, previously transferred from production to vertical production wells, the horizontal replacement of horizontal injection wells to production wells is performed and the horizontal production wells are replaced into injection wells, and the cycle repeat until the formation.

Also new is the fact that with a decrease in the production rate of the reservoir, vertical production wells in rows in one row are transferred to injection wells.

Figure 1 shows the development scheme of deposits of high viscosity oil and bitumen.

Figure 2 shows the same section of the reservoir in the context when injecting the displacing agent into the horizontal injection wells and the selection of oil bitumen from horizontal production wells.

Figure 3 shows the same section of the reservoir in the context when converting horizontal injection wells into production wells for the selection of oil bitumen and horizontal production wells into injection wells for pumping coolant.

Figure 4 shows the same section of the reservoir in the context of the transfer of vertical production wells through one for injection of coolant.

The essence of the method is as follows.

The development of reservoir 1 of highly viscous oil and bitumen (see FIGS. 1 and 2) begins with the drilling and construction of rows of vertical producers 2, 2 ', 2 ", ... 2 ⁿ and open the oil reservoir 1 within its entire thickness.

Between the rows of vertical producers 2, 2 ', 2 ", ... 2 ⁿ (at the estimated distance from the condition of the greatest coverage of reservoir 1 by subsequent heat exposure), rows 3 and 4 of horizontal wells 5', 5" are drilled and built within the reservoir 1 ', ... 5 ⁿ and 6, 6 ', 6 ", ... 6 ⁿ (see Fig. 1, 2), and the upper row 3 is a series of horizontal injection wells 5, 5', 5", ... 5 ⁿ , and the lower row 4 is a series of horizontal producing wells 6, 6 ', 6 ”, ... 6 ⁿ . A row of 3 horizontal injection wells 5, 5 ', 5 ", ... 5 ⁿ , is located in reservoir 1 above a row of 4 horizontal production wells 6, 6', 6”, ... 6 ⁿ .

Upon completion of drilling and construction (as shown in FIGS. 1, 2), as well as the arrangement of all wells with pumping equipment (not shown), the coolant (steam, hot water, gas) is pumped into the horizontal injection wells 5, 5 ', 5 "... 5 ^{n of} row 3. The coolant, having reached the reservoir 1 of highly viscous oil and bitumen, begins to heat up highly viscous and heavy oil (oil bitumen) .As a result of heating, the oil bitumen liquefies, that is, their viscosity decreases and, when heated, the oil bitumen passes through a filter (not shown) into horizontal ext washing wells 6, 6 ', 6 ”, ... 6 ^{n of} row 4, from which oil bitumen is subsequently extracted, and also heated oil bitumen flows to the filters (in FIGS. 1, 2, 3 and 4) of vertical producers 2, 2', 2 ", ... 2 ⁿ wells, which are also launched for the selection of heated oil bitumen.

The development of reservoir 1 of highly viscous oil and bitumen in this mode (see figure 2) is carried out until the coolant pumped into reservoir 1 through horizontal injection wells 5, 5 ', 5 ", ... 5 ^{n of} row 4 does not start to break into horizontal production wells 6, 6 ', 6 ”, ... 6 ^{n of} row 3. After that, the coolant is pumped into horizontal injection wells 5, 5', 5", 5 ^{n of} row 4, equipped with pumps and put into operation as production and the horizontal production wells 6, 6 ', 6 ", ... 6 ⁿ number of 3, in which the coolant is transferred to burst naked etatelnye, i.e. removed from their pumps and allowed for injection of coolant, while continuing to select petroleum bitumen of the vertical production wells 2, 2 ', 2 ", ... 2 ^n. Develop reservoir 1 Heavy Oil and Bitumen in this mode (see. FIG. 3) lead until the production rate of the reservoir 1 'decreases, which is caused by a decrease in the production of oil bitumen produced from vertical production wells 2, 2', 2 ”, ... 2 ⁿ .

In order to develop the remaining reserves of oil bitumen in the reservoir 1 ', the vertical production wells 2, 2', 2 ", ... 2 ^{n are} transferred through one to vertical injection wells for pumping coolant (see Fig. 4) and continue to develop reservoir 1 of high-viscosity oil and bitumen to the full development of the remaining reserves of oil bitumen.

Later, when the coolant breaks into horizontal production wells, they are transferred to injection wells, as described above, and the cycle repeats.

The proposed method of thermal impact on a reservoir of high viscosity oil and bitumen allows for additional involvement in the development of sections of a reservoir of high viscosity oil by drilling an additional series of horizontal production wells, which increases the coverage of thermal effects on the reservoir with the possibility of subsequent transfer of horizontal production wells to horizontal injection wells, which adds movement filtration fluid flows in it and, as a result, the coefficient of coverage and oil recovery increases and deposits.

In addition, in this method, an increase in the production of oil bitumen reserves in deposits is achieved by transferring vertical production wells to vertical injection wells for pumping coolant.

Claims (2)

1. The method of thermal impact on a reservoir of highly viscous oil and bitumen, including drilling horizontal injection wells, drilling a horizontal production well under each injection well within the same productive formation to select high viscosity oil and bitumen, pumping coolant into horizontal wells, characterized in that they drill rows of vertical production wells for the extraction of highly viscous oil and bitumen; between the rows of vertical production wells within the reservoir, the rows are mentioned After higher than horizontal wells, high-viscosity oil and bitumen are taken from horizontal production wells before the coolant breaks into the vertical production wells from horizontal injection wells, after which the coolant is pumped into horizontal injection wells and transferred to production wells, and horizontal production wells to injection wells , in the future, when the coolant breaks out from horizontal injection wells, previously transferred from production to vertical production Suitable wells produce inverse substitution translation horizontal injection wells in production wells, production wells and horizontal - in injection wells and the cycle is repeated until the generation of the formation. 2. The method according to claim 1, characterized in that when the production rate of the reservoir is reduced, the vertical production wells in rows in one row are transferred to injection wells.

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