RU2200231C2 - Process of development of oil field - Google Patents

Abstract

FIELD: oil industry. SUBSTANCE: process includes cyclic flooding with periodic injection of water into injection wells from cluster pumping station through pressure pipe-lines and extraction of oil from production wells. Injection wells are grouped depending on penetrability of pools opened in them with subsequent establishment of quality of water to be pumped into each group of injection wells. Water is specifically evaluated by three qualities. Water is characterized by different ( increasing ) contents of solid particles and by different ( increasing ) sizes of particles. Oil output is raised as water is injected through pressure pipe-lines at start of first quality, then at start of second quality and later at start of third quality without washing of these pipe-lines. EFFECT: raised oil output from production wells thanks to involvement into development of lowpenetrable oil- bearing pools. 1 dwg, 1 tbl

Description

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

 There is a method of developing oil fields with maintaining reservoir pressure by circuit and in-circuit flooding (see Prince Muravyova IM, Andrianova RS, Gimatudinova Sh.K. et al. "Development and operation of oil and gas fields" M. , Nedra, 1970, pp. 102-106).

 The advantage of the method is the simplicity of its implementation, thanks to this method has found wide application in the oil fields of the Russian Federation and the CIS.

The disadvantages of the method include:
- high energy costs for waterflooding of oil fields, as it is necessary to continuously pump water into injection wells under a pressure exceeding the reservoir pressure;
- a breakthrough of water injected into injection wells to production wells along high-permeability formations, leaving “pillars” in low-permeability formations.

 Closest to the technical nature of the proposed one is a method of developing oil fields, including cyclic flooding of reservoirs (see NTS "Oil and Gas of Tyumen", issue 12, 1971, pp. 35-38). When developing oil fields in this way, water is alternately pumped into injection wells to create pressure pulses and change its movement in the reservoirs.

 The advantage of this method is the possibility of stabilization, water cut production of production wells.

The disadvantages of the method include:
- the complexity of the control and regulation of the process of oil displacement from heterogeneous permeability formations;
- the need to flush pressure pipelines, which during transverse injection of water into the wells stand idle for at least half the calendar time.

 The aim of the proposed method is to increase oil production from production wells due to the involvement of low-permeability oil reservoirs in the development.

 The goal is achieved by the described method of developing oil fields, including cyclic flooding.

 What is new is that injection wells in oil fields are grouped depending on the permeability of the formations uncovered in them, followed by establishing the quality of water for injection into each group of wells and, on this basis, increasing oil production from production wells.

 Of the available sources of patent and technical writers, we do not know the claimed combination of distinctive features. Therefore, the proposed method for the development of oil fields meets the criterion of "significant differences".

 The drawing shows a diagram of the implementation of the proposed method in one of the sections of the Romashkinskoye oil field.

 The site is developed by the method of cyclic flooding using basic quality water containing 20-25 mg / l of suspended solid particles up to 32 microns in size. In this case, periodically every 10 days from the cluster pumping station “A”, water is pumped through injection pipe “B” into injection wells 1–4, through pipeline “B” - into wells 5–8 and through pipeline “G” - into wells 9 -12 for 5 days, measuring the volume extracted from production wells 13-32 oil-water emulsions, including oil, pressure and volume of water injection into injection wells for each pipeline, power consumption for cyclic flooding.

Following a more or less accepted sequence of cyclic flooding of the site, 17.5-18.3 thousand m ^{3 of} water are pumped into injection wells under pressure of 150-160 kg / cm ² every month, and 16.9-17.1 thousand are produced from production wells .m ³ oil-water emulsions, incl. 2.8-3.1 thousand m ^{3 of} oil with a density of about 0.87 g / cm ³ .

Concrete example
The injection wells operating in the area of the oil field are divided into three groups according to the permeability of the layers discovered in them. Wells 2, 3, 5, 8, and 11, which opened formations with a permeability of 0.013-0.14 darsi, were assigned to group 1, wells 2, 6, 10, and 12, which opened formations with a permeability of 0.14-0.25 darsi, and 3 - wells 4, 7 and 9, which revealed formations with a permeability of 0.25 darsi and above.

 Experimental studies have established that water of quality 1 containing no more than 5 mg / l of solid particles up to 2 microns in size is required for injection into wells of group 1; water of quality 2 containing no more than 10 mg / l of solid particles up to size 2 in wells of group 2 is required 4 microns, in wells of group 3 - quality 3 water containing not more than 15 mg / l of solid particles up to 6 microns in size.

 By agreement with the management of the development of the oil field, cyclic flooding of the field is carried out as follows.

 Periodically every 10 days, water of quality 1 is pumped into wells of group 1, water of quality 2 into wells of group 2 and quality 3 water into wells of group 3 for 5 days through the same pressure pipes without flushing. At the same time, the volume of oil-water emulsion production from production wells is systematically measured, including oil, pressure and water injection volumes of quality 1, 2 and 3 into wells of groups 1, 2 and 3.

 The averaged technical and economic indicators of the development of the oil field using the known and proposed method are shown in the table.

 The data presented in the table show that the proposed method for developing a section of an oil field is more effective than the known one. The use of different quality water permeability for cyclic waterflooding of reservoirs during the development of an oil field allows increasing oil production from production wells and injectivity of injection wells, and reducing the energy consumption for pumping water into them.

 According to rough estimates, the economic efficiency of the development of an oil field by the proposed method is about 75 million rubles. per month or 900 million rubles. per year due to involvement in the development of low permeability formations along with high permeability formations.

Claims (1)

 A method of developing oil fields, including cyclic flooding with periodic injection of water into injection wells from a well pump station through pressure pipelines and oil production from production wells, characterized in that the injection wells are grouped depending on the permeability of the formations hidden in them, with subsequent establishment of water quality for injection into each group of injection wells, for which the water quality is characterized, in particular, by the example of 3 qualities, where water of 1 quality contains t, for example, not more than 5 mg / l of solid particles up to 2 microns in size, quality water 2 contains, for example, not more than 10 ml / l of solid particles up to 4 microns, quality water 3 contains, for example, not more than 15 ml / l solid particles up to 6 microns in size, while oil production is increased on this basis by the fact that water is pumped through pressure pipelines at first 1 quality, then 2 quality and then 3 quality without washing these pipelines.

Images