RU2129656C1 - Method of oil pool development - Google Patents

Abstract

FIELD: oil producing industry, in particular, methods of development of oil pools. SUBSTANCE: method includes determination of well water encroachment nature, selection of wells for treatment and performance of well treatment. Nature of water encroachment of wells is determined by subdividing the parameters of formation pressure, water encroachment and source of water encroachment into intervals and ranking of each parameter in each interval. Water-free wells with water cutting of their production within 0-30% and formation pressure exceeding the hydrostatic pressure are assigned rank 0. Wells with formation water cutting of their production within 30-80% and formation pressure equalling the hydrostatic pressure are assigned rank 1. Wells with injected water cutting of their production above 80% and formation pressure below the hydrostatic pressure are assigned rank 2. Then sum of ranks is found for each well, and well development method is selected depending on the sum magnitude. If sum of ranks is less than 2, well is treated with acid compositions. If sum of ranks is from 3 to 4, temporary blocking of water saturated zones is undertaken with subsequent treatment with acid compositions. If sum of ranks exceeds 4, shutoff of formation water saturated zones is effected with subsequent treatment with acid compositions. EFFECT: selection of the most efficient methods of well treatment and increased oil production due to ranking of well development parameters. 3 tbl

Description

 The invention relates to the oil industry, and in particular to methods for developing oil deposits.

 A known method of developing an oil field, including drilling production and injection wells, water injection and product selection with volume measurement, where for each well and for the entire field determine the current coefficient of energy oil recovery (KEN) and the type of impact is selected depending on the value of KEN [1] .

 In this development method, only the water cut indicator of the product without taking into account its nature and dynamics is used to determine the CES, which is not enough to effectively influence the reservoir.

 There is a method of monitoring the development of an oil reservoir, including ranking the flow rates of water in descending order and flow rates of oil in ascending order, the effect on the reservoir taking into account the sum of the ranks [2].

 However, in the known method, the ranking is carried out according to 2 parameters: oil and water production, however, the boundaries of the ranks are not precisely defined, the nature of flooding is not taken into account. Also, the possibility of impacting wells using known or new technologies is not provided.

 The closest in technical essence and the achieved effect is a method of developing an oil reservoir, including determining the nature of watering according to the dynamics of accumulated oil production, changing the selection of fluids, choosing wells to isolate high-watering intervals, and conducting insulation work [3].

 In the known method, the dynamics of oil production is analyzed without taking into account other parameters of the wells, they do not consider the possibility of implementing complex methods of influencing the well, which reduces the effectiveness of the method.

 The present invention is based on the task of creating a method for developing an oil reservoir, which allows, by ranking the performance of the well, to select the most effective method of stimulating oil production and, thereby, increasing oil production.

 The problem is solved by creating a method of developing an oil field, including determining the nature of watering of producing wells, selecting wells for processing and processing, where the nature of watering of wells is determined by dividing the reservoir pressure, water cut and water supply source into intervals with assigning a rank to each indicator in this interval , for waterless wells, but with a water cut of 0-30% and with reservoir pressure above hydrostatic, rank 0, for wells with a well with a production date of 30-80% watered with produced water and with a reservoir pressure equal to hydrostatic, rank 1, and for wells with a water cut of more than 80% watered with injected water and with a reservoir pressure below hydrostatic, rank 2, then find the sum ranks for each well, and depending on its size, the method of processing the well is chosen, and with the sum of ranks from 0 to 2, acid compositions are processed, with the sum of ranks from 3 to 4, a temporary blocking of saturated n formation followed by treatment with acidic compositions, and with a rank of> 4, isolation of water-saturated zones of the formation is carried out, followed by treatment with acidic compositions.

 Indicators: reservoir pressure, water cut and watering source are selected as the most informative, based on the efficiency of using hydrochloric acid and compositions based on it to intensify oil production from carbonate reservoirs of specific deposits in Tataria, Bashkiria and Perm region. Each indicator is divided into intervals and assign to each interval a rank from 0 to 2 (see table 1).

 Then, for each well, the sum of the ranks is calculated and, with the sum of the ranks from 0 to 2, the bottom-hole zone is treated with acid compositions to increase well productivity; with the sum of ranks from 3 to 4, a temporary blocking of the water-saturated zones of the formation is carried out for the duration of the reaction of the injected acid compositions with the bottomhole rock and saturating fluids, after the end of the reaction, the blocking stops; when the sum of ranks> 4, conduct insulating work to isolate water-saturated zones and then conduct treatment with acidic compositions to increase the permeability of the bottomhole zone (see table 2). As a result, along with the intensification of oil production, there is a reduction in water production.

As acidic compositions can be used:
hydrochloric acid according to TU 6-01-04684381-85-92, TU 6-01-714-77;
compositions of the type SNPCH-9010 according to TU 39-5765657-131-91;
hydrochloric acid compositions of delayed action (see Ibragimov GZ, Fazlutdinov KS, Khisamutdinov NI Application of chemical reagents for the intensification of oil production. Handbook. M: Nedra, 1991, p. 31-32).

Temporary blocking before injection of acidic compositions can be carried out using, for example:
process fluid type SNPCH-3100 according to TU OP13-0281036-25-92;
hydroemulsion solutions (see Bykov MT et al., "Collection of technological instructions for enhancing oil recovery and overhaul of wells", Tatneft, Leninogorsk, 1978, v.2, p.21-23).

Waterproofing works are carried out using:
water-cement suspensions (see Muslimov R.Kh. et al. Geology, development and operation of the Romashkinskoye oil field, M .: VNIIOENG, v.2, p. 174-220);
synthetic resins according to TU 88-109-71, gipan MRTU 6-01-166-67;
compositions of selective action DNPCH-8700 according to TU 39-05675760-OP-214-95, SNPCH-9630 according to TU 39-5765657-097-90.

 The method is as follows.

 Based on a comparison of the average oil production rate of producing wells by reservoir (2.2 tons / day) for specific wells, wells that are promising for work to intensify production are pre-selected. Further, wells that do not meet the requirements of the technical condition (lack of a sump, violation of the integrity of the column, malfunction of the wellhead fittings) and environmental protection are screened out. For the remaining wells, the dynamics of fluid production is analyzed by its nature - the source of watering, water cut and reservoir pressure, the indicators are ranked by dividing the indicators into intervals with assignment of ranks from 0 to 2, the sum of the ranks is calculated and the technology for processing is selected.

 We consider the implementation of the method using the example of a deposit of the Kizelovskoye horizon of the NGDU Leninogorskneft at 8 selective production wells. The deposit has been in operation since 1974. The reservoir is represented by pore-cavernous-fractured limestones, the initial oil saturation is 71%. The average oil production rate is 2.2 tons / day. Foundation 1264 wells. Wells are selected for oil stimulation work. The indicators of watering, reservoir pressure and the source of watering are determined, divided into intervals with assignment of ranks from 0 to 2, the sum of the ranks is calculated and, depending on the amount, a specific technology for processing the well is selected.

 On wells 15353, 26450, 16975, 16889, 37771, the recommended and implemented technologies coincided. Additional oil production amounted to 398, 591, 240, 302, 380 tons, respectively. At wells 15547, 9363, 15360, the recommended and implemented technologies did not coincide; there is no additional oil production using the existing technology (see table 3). The annual technological effect (1996) only in the fields of Tatarstan with the help of the claimed invention - more than 18.1 thousand tons of oil were additionally produced.

 The technical and economic advantage of the proposed method is that, unlike the known method, it allows the analysis of a small amount of geological and field information to quickly and reliably determine the promising processing technology for each well and, as a result, increase the efficiency of field work.

Claims (1)

 A method of developing an oil field, including determining the nature of watering wells, selecting wells for processing and processing, characterized in that the nature of watering wells is determined by dividing the reservoir pressure, water cut and water source into intervals with assigning a rank to each indicator in this interval: for anhydrous wells with a water cut of 0–30% and reservoir pressure above hydrostatic are assigned a rank of 0, for wells with a water cut of 30–80%, waterlogged I am assigned reservoir water with a reservoir pressure equal to hydrostatic, rank 1, and for wells with water cuts of more than 80%, waterlogged with injected water, and with reservoir pressure below the hydrostatic pressure, they are assigned rank 2, then the sum of the ranks for each well is found and, in depending on its size, a well treatment method is chosen, and with a total of ranks <2, treatment with acidic compositions is carried out, with a total of ranks from 3 to 4 a temporary blocking of water-saturated zones of the formation is carried out, followed by acid treatment compositions, and when the sum of ranks> 4 carried isolation reservoir zones saturated with subsequent treatment with acidic compositions.

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