RU2431745C1 - Method for development of deposit of heavy oil or bitumen with implementation of two well head horizontal wells - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: procedure consists in construction of double well-head horizontal wells, in heat carrier pumping through upper - pressure well with payout bed heating and creation of steam chamber, in withdrawal of production through lower - producing well, in pickup of thermogram of steam chamber, and in analysis of condition of its heating for uniformity of heating and presence of temperature peaks. The steam chamber is uniformly heated on base of obtained thermograms. A process double well head wells is constructed above the pressure well at distance eliminating outbreak of heat carrier. Pickup of steam chamber thermogram is carried out on data of thermo-sensors positioned in process and producing double well head horizontal wells. Geo-physical analysis is performed from side of both well heads for control of uniformity of steam chamber heating. During development of deposit of heavy oil or bitumen production from both well heads is periodically sampled for evaluation of salinity of samples water. Salinity of water is correlated to presence of temperature peaks on thermograms of the steam chamber, where upon there changed filtration direction and/or modes of heat carrier pumping and withdrawal of production for equalising temperature in the steam chamber.

EFFECT: raised efficiency of procedure.

2 cl, 1 tbl, 1 dwg

Description

The invention relates to the oil industry and may find application in the development of a highly viscous and bituminous oil field using double-well horizontal wells.

A known method of developing a heterogeneous oil bitumen deposit (RF patent No. 2287678, IPC 8 ЕВВ 43/24, published in Bulletin No. 32 of 11/20/2006), including the construction of a producing double-well horizontal well and selection of products, characterized in that it is higher than the producing double-well horizontal wells build a parallel double-well horizontal injection well parallel to it, thereby creating a pair of double-well horizontal wells; a similar pair of double-well horizontal wells, a pair of double-well horizontal core wells are carried out separately, covering the most productive zones of the reservoir, the operating modes of the pairs of double-mouth horizontal wells for injection are established taking into account the characteristics of each section of the reservoir, the coolant is pumped into the upper injection double-mouth horizontal wells from both mouths, and production is selected from the producing double-mouth horizontal wells with a swab pump moreover, the swab pumps of adjacent producing double-mouth horizontal wells are connected to each other.

The disadvantage of this method is the limited application, which can be done only if there are adjacent pairs of dual-well injection and production wells.

Also known is a method of developing an oil field (RF patent No. 2211318, IPC 8 EV 43/24, published in Bulletin No. 24 of 08/27/2003), including drilling a continuous (double-well) well with the formation of its output section upward with an inclination from the reservoir to the surface, installing a casing in a drilled well, cementing the annulus along the entire length, perforating the casing in the horizontal section, installing tubing with centralizers inside the casing, supplying heat For the tubing string from the inlet and outlet sections, product selection at the outlet section while continuing to pump coolant through the inlet section.

The disadvantage of this method is the lack of efficiency of oil recovery, because when steam is injected and oil is taken from one well at the same time, quick steam breakouts occur, and during cyclic exposure, the steam is unproductive for re-heating the cooled reservoir during the selection period, i.e. high energy consumption.

The closest in technical essence is the method of developing a heavy oil or bitumen field using double-well horizontal wells (RF patent No. 2340768, IPC 8 ЕВВ 43/24, published in bulletin No. 32 of December 10, 2008), including the injection of coolant through two-well horizontal injection well, heating of the reservoir with the creation of a steam chamber and selection of products through the two-mouth horizontal production well, while heating of the reservoir begins with steam injection in both wells, heat the intersection the important zone of the formation, reduce the viscosity of oil or bitumen, and the steam chamber is created by pumping coolant with the possibility of punching the latter to the top of the reservoir and increasing the size of the steam chamber during the selection process, in which thermograms of the steam chamber are taken, the state of its heating for uniformity of heating is analyzed and the presence of temperature peaks, and taking into account the obtained thermograms, the steam chamber is uniformly heated by changing the filtration direction and / or the coolant injection modes product selection, thus the volume pumping coolant 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 disadvantages of this method are:

- firstly, the uniformity of the heating of the steam chamber and the presence of temperature peaks are made only according to the obtained thermograms, and in the event of failure of one or more temperature sensors or a break in the fiber-optic cable, control over the uniformity of heating of the steam chamber is lost, which can lead to erroneous changing the direction of filtration and / or the modes of pumping coolant and product selection and, as a result, reducing the efficiency of developing a heavy oil or bitumen field using a two-well horizontal well;

- secondly, in addition to the obtained thermograms, there is no possibility of complementary (duplicate) control over the state of uniformity of heating of the steam chamber.

An object of the invention is to increase the efficiency of developing a heavy oil or bitumen deposit using double-well horizontal wells with the possibility of additional (duplicate) control over the uniformity of heating of the steam chamber.

The stated technical problem is solved by the method of developing a heavy oil or bitumen field using double-well horizontal wells, including the construction of double-well horizontal wells, pumping coolant through the upper - injection - well with heating the reservoir and creating a steam chamber, and product selection through the lower - producing - well, I’ll take a steam chamber thermogram, analyze the state of its heating for uniform heating and the presence of temperature peaks, and taking into account the obtained thermograms carry out uniform heating of the steam chamber by changing the direction of filtration and / or the modes of pumping coolant and product selection.

What is new is that above the injection well at a distance that excludes the breakthrough of the coolant, a technological double-well well is built, and the thermograms of the steam chamber are taken according to the temperature sensors that are placed in the technological and producing double-well horizontal wells, while geophysical are produced from both mouths of the technological well research to control the uniformity of heating the steam chamber, and in the process of developing a heavy oil or bitumen deposit periodic sampling of products from both mouths of the control well is carried out to assess the mineralization of the water in the samples, based on the mineralization of this water, compare it with the presence of temperature peaks in the thermograms of the steam chamber, after which they change the filtration directions and / or the modes of pumping the coolant and product selection for temperature equalization in the steam chamber.

Also new is the fact that a two-well technological well can, if necessary, be used as a production well.

The drawing schematically shows the proposed method for the development of heavy oil or bitumen deposits using double-well horizontal wells. First, the construction of the upper injection 1 (see drawing) and lower production wells 2 with horizontal sections 3 and 4, respectively, located one above the other and opening the reservoir 5 with heavy oil or bitumen, is carried out, and during the construction of injection 1 and production 2 wells horizontal sections 3 and 4 are respectively equipped with filters 6 and 7.

An injection well 1 is used to pump coolant into a producing formation 5, and a producing well 2 is used to produce heavy oil or bitumen (products) from the producing formation 5.

Next, the injection well 1 is equipped with tubing strings (tubing) 8 and 8 'perforated holes 9 and 9', respectively. The production well 2 is provided with tubing strings 10 and 10 'with pumps 11 and 11', respectively. Above injection 1 and producing 2 wells at a distance that excludes coolant breakthrough (at least 5 meters), a production well 12 is constructed with a horizontal section 13 equipped with a filter 14. In production 12 and production 2 two-well wells are run on fiber optic cables from both mouths and along the entire length of the trunks 13 and 4, respectively, temperature sensors 15 and 16.

They start to pump coolant (steam) from the steam generator (not shown in the drawing) into the reservoir 5 from both mouths of the injection well in a ratio of 50:50 through tubing strings 8 and 8 'through their perforated holes 9 and 9', respectively, and also filter 6 horizontal section 3 of injection well 1.

Depending on the permeability of the reservoir 5, the injection pressure is selected, and depending on the effective oil-saturated thickness of the reservoir 5, the volume of injected steam is determined, and the reservoir 5 is heated to create a steam chamber.

The products are selected from the double-mouth production well 2, while the heated products through the filter 7 of the horizontal section 4 of the production well 2 are received by the pumps 11 and 11 ', which respectively raise the products to the day surface from both mouths of the double-well production through the tubing strings 10 and 10' well 2 in a ratio of 50:50.

To clarify the technological parameters of the horizontal wellbore (HS) in the work (abstract of the dissertation of M.I. Amerkhanov UDC 622.276.031: 532.5 “Study of the conditions for the effective use of horizontal wells at development sites with hard-to-recover oil reserves, page 17), it is proposed to use the results of mineralization analysis and composition of produced water.

It was established that the oil production rate significantly correlates with the temperature at the wellhead and the total salinity of the produced water. Moreover, the flow rate is proportional to the temperature of the produced fluid (T °, C) and inversely proportional to the amount of mineralization (M, g / l):

Q _gf = 0.21 · T-1.38 · M-4.33

The correlation coefficient of the model reflects by 79% the variability of the flow rate of the HS. The standard error is 2.6, and its value can be used to set prediction boundaries for new observations.

After a prolonged injection of the coolant and selection of products according to the readings of temperature sensors 15 and 16, thermograms of the steam chamber are constructed that characterize the state of heating of the steam chamber between horizontal sections 13 and 4 of technological 12 and production 2 wells, respectively.

The obtained thermograms from temperature sensors 15 and 16 are analyzed for uniformity of heating of the steam chamber and for the presence of temperature peaks. If the thermogram shows uneven heating of the steam chamber (the temperature in a certain zone is much lower than in others), or the appearance of sharp peaks, or insufficient heating of the steam chamber, taking into account the obtained thermograms, the steam chamber is uniformly heated.

At the same time, using a sampler of any known design, product samples are taken from both mouths of the control well 12.

Samples are analyzed and the mineralization of the produced water is determined on both sides of the dual-well technological well 12.

In the selected products, in addition to high-viscosity oil and condensed water, there is a simultaneously selected high-salinity produced water. Mineralization of produced water when mixed with condensate is reduced. With constant injection and selection, an equilibrium relationship is established between the amount of highly viscous oil produced and the mineralization of the water taken along the way. In this case, it is possible to establish the ratio of the volumes of produced water and condensate and the degree of uniformity of the heating of the inter-well zone, using this data to control the modes of production selection and steam injection at the mouths of the wells.

The mineralization value of produced formation water is compared with the presence of temperature peaks in the thermograms of the steam chamber, after which the filtration directions and / or the modes of coolant injection and product selection are changed by changing the ratio of the coolant injection volumes (10% -90%) :( 90% -10%) through the first or second wellhead of the injection well and production volumes (10% -90%) :( 90% -10%) through the first or second wellhead of the producing well as follows:

- with a sharp decrease in the mineralization of produced formation water in the samples taken from one of the mouths of the technological well relative to the opposite mouth of the same well, as well as the presence of a synchronous temperature peak (temperature increase in a small area) in the thermograms of the steam chamber from the same side in the producing and technological wells change the operating mode by reducing the volume of coolant pumped into the injection well and the selection of products from the producing well from the side of these mouths, while from the opposite mouths of the injection and production wells respectively increase the volumes of coolant injection and production selection;

- with a sharp increase in the mineralization of products in the samples taken from one of the mouths of the technological well relative to the opposite mouth of the same well, as well as the absence of a synchronous temperature peak (lowering the temperature in a small area) in the thermograms of the steam chamber from the same side in the producing and technological wells change operating mode by increasing the amount of coolant pumped into the injection well and taking products from the producing well from the side of these mouths, while from the side of ivopolozhnyh mouths of injection and production wells, respectively, reduces the amount of injection of coolant and product selection.

The volume of coolant pumped through the mouth of the injection well and / or the selection of products through the mouth of the producing well increases and / or decreases until equilibrium mineralization of the produced product is observed, observed before the temperature changes.

Case Study

An analysis of the samples taken from both mouths of the production well 12 showed that, from the right mouth, the mineralization of produced formation water sharply decreased and more than three times exceeds the mineralization of products taken from the left mouth of the technological well 12, as well as data from thermograms taken from temperature sensors 15 and 16, placed along the entire length of the technological 12 and producing 2 wells, shows the synchronous temperature peak on the thermograms of the steam chamber in both wells on the right side of the thermogram, which indicates a possible breakthrough of the coolant in the horizontal section 4 of the producing well 2 on the right side, while the left side of the thermogram is much lower in absolute temperature, which indicates the uneven heating of the steam chamber.

After that, the volume of coolant pumped through the right mouth of the horizontal injection well 1 is reduced and the volume of coolant is pumped through the left mouth of the horizontal injection well 1, for example, in the ratio of 70%: 30%.

Also reduce the volume of production through the right mouth of the horizontal production well 2 and increase the volume of production through the left mouth of the horizontal production well 1, for example, in the ratio of 70%: 30%.

After pumping the calculated volume of water, re-sampling and analysis of product samples from both mouths of the production well 12 is performed, while on the right mouth, the mineralization of products exceeds 1.1-1.2 times the mineralization rates of samples taken from the left mouth of the production well 12, and taking thermograms with the help of temperature sensors 15 and 16, placed along the entire length of the technological wells 12 and producing 2 wells, in which there are no synchronous temperature peaks, indicating a shift in the temperature field on the right side thermograms in technological 12 and producing 2 wells in the right direction and uniformity of heating in the steam chamber.

The front of the steam chamber warms up and the coverage area of the evenly heated zone of the steam chamber is increased, as a result of which the formation is covered by thermal exposure, which leads to an increase in the selection of heavy oil or bitumen.

Uniform heating of the steam chamber directly affects the efficient production of high-viscosity oil reserves, which in turn affects the oil recovery coefficient (CIN) and flow rate. If necessary, you can perform additional geophysical surveys, such as descent of the level gauge and others.

The dual well production well 12, if necessary, can be used as a production well for product selection.

The implementation of this method allows to increase the efficiency of the development of a heavy oil or bitumen deposit due to the construction of a dual-well technological well above a double-well well, which allows complementary (duplicate) monitoring of the uniformity of heating of the steam chamber by periodic sampling of products from both mouths of the technological well with subsequent assessment of the mineralization of the well in a water sample and comparing it with those taken in production and production wells thermograms followed by a change in the direction of filtration and / or the modes of pumping coolant and product selection.

Claims (2)

1. A method of developing a heavy oil or bitumen field using horizontal double-well wells, including the construction of horizontal horizontal wells, pumping coolant through the upper — injection well with heating the productive formation and creating a steam chamber, and selecting products through the lower — producing well, taking a steam chamber thermogram , analysis of the state of its heating for uniformity of heating and the presence of temperature peaks, and taking into account the obtained thermograms carry out uniform heating steam chamber, characterized in that above the injection well at a distance that excludes the breakthrough of the coolant, build a technological wellhead, and the thermogram of the steam chamber is taken according to the temperature sensors that are placed in the technological and producing double mouth horizontal wells, while on the side of both mouths of the technological well conduct geophysical studies in order to control the uniformity of heating the steam chamber, moreover, in the process of developing a heavy oil field and whether bitumen conducts periodic sampling of products from both mouths of the control well to assess the mineralization of the water in the samples, based on the mineralization of this water, compare it with the presence of temperature peaks in the thermograms of the steam chamber, and then change the filtration directions and / or the coolant injection and sampling modes products for equalizing the temperature in the steam chamber. 2. The method of developing a heavy oil or bitumen deposit using double-well horizontal wells according to claim 1, characterized in that the double-well technological well can, if necessary, be used as a production well.

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