RU2616010C1

RU2616010C1 - Recovery method of zone-heterogenetic oil reservoirs by impulse low-mineralized water flooding

Info

Publication number: RU2616010C1
Application number: RU2016124188A
Authority: RU
Inventors: Наиль Ульфатович Маганов; Раис Салихович Хисамов; Вадим Валерьевич Ахметгареев; Венера Гильмеахметовна Базаревская
Original assignee: Публичное акционерное общество "Татнефть" им. В.Д.Шашина
Priority date: 2016-06-19
Filing date: 2016-06-19
Publication date: 2017-04-12

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method is carried out by a cyclic increase and decrease in working substance injection pressure in injection wells. Low-mineralized water is used as a working substance. Injection well is placed in the center. Production wells are arranged around this well. Allowed range of oil-saturated reservoir permeability at the source area is not less than 30%. Low-mineralized water is taken from surface watercourses: rivers, lakes and seas. Water is pre-decontaminated and pre-filtered to suspended solids size less than 0.1 of average reservoir pore size with minimum permeability. Water injection to the injection well is started with a gradual increase in consumption from zero to the value at which injection pressure is (0.7-0.8)*P_rock where P_rock is vertical rock pressure of overlying rocks. Consumption is then reduced to the value at which injection pressure is (0.1-0.2)⋅P_rock. Cycles of increasing/decreasing of low-mineralized water consumption are repeated many times. Consumption increasing and decreasing speed is set equal at the range of 2-50 m³/day per one injection well. Bhp value relation in source production wells is set inversely proportional to their reservoir permeability-formation thickness product.

EFFECT: increased oil recovery of zone-heterogeneous oil reservoirs.

Description

Способ разработки зонально-неоднородных нефтяных коллекторов импульсным низкоминерализованным заводнением, включающий циклическое повышение и снижение давления закачки рабочего агента в нагнетательных скважинах, применение в качестве рабочего агента низкоминерализованной воды, отбор продукции из добывающих скважин, отличающийся тем, что выбирают очаг с нагнетательной скважиной в центре и добывающими скважинами вокруг, при этом разброс проницаемости нефтенасыщенного коллектора по площади очага составляет не менее чем 30%, низкоминерализованную воду используют с поверхностных водоемов – рек, озер, морей, которую предварительно обеззараживают и фильтруют до размеров твердых взвешенных частиц не более 0,1 от среднего размера пор коллектора с минимальной проницаемостью, закачку воды начинают вести в нагнетательную скважину с постепенным повышением расхода от нуля до значения, при котором давление закачки составляет (0,7-0,8)·Р_гор, где Р_гор – вертикальное горное давление вышележащих пород, после чего расход уменьшают до значения, при котором давление закачки составляет (0,1-0,2)·Р_гор, циклы увеличения–уменьшения расхода низкоминерализованной воды повторяют многократно, причем скорость как увеличения, так и уменьшения расхода задают одинаковой – 2-50 м³/сут на одну нагнетательную скважину, соотношение забойных давлений в добывающих скважинах очага устанавливают обратно пропорционально произведению проницаемости их коллектора на толщину пласта.A method for developing zone-heterogeneous oil reservoirs by pulsed low salinity water flooding, including cyclically increasing and decreasing the injection pressure of a working agent in injection wells, using low-mineralized water as a working agent, selecting products from production wells, characterized in that they select a source with an injection well in the center and producing wells around, while the spread of permeability of the oil-saturated reservoir over the source area is not less than 30%, low ralized water is used from surface water bodies - rivers, lakes, seas, which are pre-disinfected and filtered to a size of solid suspended particles of not more than 0.1 from the average pore size of the collector with minimal permeability, water is pumped into the injection well with a gradual increase in flow from zero to a value at which the injection pressure is (0.7-0.8) · P _mountains , where P _mountains is the vertical rock pressure of the overlying rocks, after which the flow rate is reduced to a value at which the injection pressure is t (0.1-0.2) · P _mountains , the cycles of increasing – decreasing the flow rate of low-saline water are repeated many times, and the rate of both increasing and decreasing the flow rate is set to the same - 2-50 m ³ / day for one injection well, the bottomhole ratio the pressure in the producing wells of the source is set inversely to the product of the permeability of their reservoir by the thickness of the reservoir.

Claims

A method for developing zone-heterogeneous oil reservoirs by pulsed low salinity water flooding, including cyclically increasing and decreasing the injection pressure of a working agent in injection wells, using low-mineralized water as a working agent, selecting products from production wells, characterized in that they select a source with an injection well in the center and producing wells around, while the spread of permeability of the oil-saturated reservoir over the source area is not less than 30%, low ralized water is used from surface water bodies - rivers, lakes, seas, which are pre-disinfected and filtered to a size of solid suspended particles of not more than 0.1 from the average pore size of the collector with minimal permeability, water is pumped into the injection well with a gradual increase in flow from zero to a value at which the injection pressure is (0.7-0.8) · P _mountains , where P _mountains is the vertical rock pressure of the overlying rocks, after which the flow rate is reduced to a value at which the injection pressure is t (0.1-0.2) · P _mountains , the cycles of increasing – decreasing the flow rate of low-saline water are repeated many times, and the rate of both increasing and decreasing the flow rate is set to the same - 2-50 m ³ / day for one injection well, the bottomhole ratio the pressure in the producing wells of the source is set inversely to the product of the permeability of their reservoir by the thickness of the reservoir.