A w/o/w active heavy oil plugging agent for oil wells and its preparation method

Abstract

The invention discloses a W / O / W type active viscous oil blocking agent. The blocking agent comprises internal phase water, viscous oil and external phase water. A nonionic surfactant is adopted between the internal phase water and the viscous oil. An ionic surfactant is adopted between the viscous oil and the external phase water. According to the invention, a W / O / W composite structure is adopted, W / O with a relatively large viscosity is coated by the external phase water layer, such that defects in prior arts of high viscosity, high construction pressure and poor selectivity upon an oil-water layer during an active viscous oil blocking agent injection process are overcome. With the blocking agent provided by the invention, the ground fluidity is good, and the injection pressure is low. When the blocking agent enters the stratum, the emulsion is demulsified, and W / O emulsion with a high viscosity is released, such that oil well water exits can be effectively blocked, and defects of existing active viscous oil blocking agents are overcome. The technical scheme provided by the invention is especially suitable for technical features of offshore oilfields.

Description

technical field

[0001] The invention relates to an active heavy oil plugging agent for oil wells, in particular to a W / O / W type active heavy oil plugging agent and a preparation method. Background technique

[0002] Water production from oil wells is a common problem in oilfield development. The harm caused by the water output of oil wells is very obvious, such as reducing oil production, increasing water production, and increasing the cost of water treatment. In order to solve this problem, people use a variety of blocking agents for water blocking, including: cement, resin, particles, gel, inorganic precipitation, etc. But the plugging agent mentioned above does not have the characteristics of real water blocking and oil blocking.

[0003] In order to reduce the damage of plugging agents to oil layers, people have done a lot of work. Among them, heavy oil plugging agents are currently recognized as one of the few selective plugging agents. The use of thick oil plugging ...

Examples

Embodiment 1

[0026] Take the sewage produced by the J platform of Suizhong 36-1 oilfield in Bohai Sea, and measure the sum of calcium and magnesium ions in the sewage to be 420mg / L. Add 4515mg / L disodium ethylenediaminetetraacetic acid to complex calcium and magnesium ions in water.

[0027] Add 3wt% of nonylphenol polyoxyethylene ether-4 to the heavy oil produced by the J platform of Suizhong 36-1 oilfield in Bohai Sea, mix well, and then slowly add 30wt% of the heavy oil's preparation water, while adding water continuously Stir and stir for 50 minutes to form a W / O emulsion containing 30 wt% of internal phase water.

[0028] Add 2wt% sodium dodecylsulfonate to the prepared water after treatment, mix well and use it as the prepared water for the external phase; add the prepared W / O emulsion containing the internal phase water into the prepared water for the prepared external phase, and the prepared external phase The weight of the prepared water is 80% of the weight of the prepared W / O e...

Embodiment 2

[0030] In the 5000Kg Bohai Nanpu 35-2 oilfield production sewage, after measuring the calcium and magnesium ion content in the sewage, add 2.42Kg of disodium edetate according to the molar ratio of the complexing agent to the sum of calcium and magnesium ions 1:1 As preparation water.

[0031] Add 105Kg of sorbitan stearate to 3500Kg Nanbao 35-2 oilfield heavy oil, mix well, then slowly add 1500Kg of preparation water, and keep stirring during the water addition process, stir for 20 minutes, and make 5105Kg of water 29.4% W / O emulsion.

[0032] Add 70Kg sodium dodecyl carboxylate to 3400Kg preparation water, mix well; add 5105Kg W / O type emulsion prepared into it, stir for 10 minutes, and make 8575Kg W / O / W type thick oil plug agent.

Embodiment 3

[0034] Take the sewage produced by the J platform of Suizhong 36-1 oilfield in Bohai Sea, and measure the sum of calcium and magnesium ions in the sewage to be 420mg / L. Add 4515mg / L disodium ethylenediaminetetraacetic acid to complex calcium and magnesium ions in water.

[0035] Add 5wt% sorbitan fatty acid esters to the heavy oil produced at the J platform of Suizhong 36-1 oilfield in Bohai Sea, mix well, then slowly add 50wt% water for preparation of the heavy oil weight, and keep stirring during the water addition process, Stir for 50 minutes to prepare a W / O emulsion containing 40 wt% of internal phase water.

[0036] Add 3wt% sodium lauryl fatty acid sodium lauryl fatty acid to the prepared water after treatment, mix well and use it as external phase preparation water; add the prepared W / O emulsion containing internal phase water into the prepared external phase preparation water, and prepare the external phase preparation water The weight of water is 100% of the weight ...

technical field

[0001] The invention relates to an active heavy oil plugging agent for oil wells, in particular to a W / O / W type active heavy oil plugging agent and a preparation method. Background technique

[0002] Water production from oil wells is a common problem in oilfield development. The harm caused by the water output of oil wells is very obvious, such as reducing oil production, increasing water production, and increasing the cost of water treatment. In order to solve this problem, people use a variety of blocking agents for water blocking, including: cement, resin, particles, gel, inorganic precipitation, etc. But the plugging agent mentioned above does not have the characteristics of real water blocking and oil blocking.

[0003] In order to reduce the damage of plugging agents to oil layers, people have done a lot of work. Among them, heavy oil plugging agents are currently recognized as one of the few selective plugging agents. The use of thick oil plugging ...

Examples

Embodiment 1

[0026] Take the sewage produced by the J platform of Suizhong 36-1 oilfield in Bohai Sea, and measure the sum of calcium and magnesium ions in the sewage to be 420mg / L. Add 4515mg / L disodium ethylenediaminetetraacetic acid to complex calcium and magnesium ions in water.

[0027] Add 3wt% of nonylphenol polyoxyethylene ether-4 to the heavy oil produced by the J platform of Suizhong 36-1 oilfield in Bohai Sea, mix well, and then slowly add 30wt% of the heavy oil's preparation water, while adding water continuously Stir and stir for 50 minutes to form a W / O emulsion containing 30 wt% of internal phase water.

[0028] Add 2wt% sodium dodecylsulfonate to the prepared water after treatment, mix well and use it as the prepared water for the external phase; add the prepared W / O emulsion containing the internal phase water into the prepared water for the prepared external phase, and the prepared external phase The weight of the prepared water is 80% of the weight of the prepared W / O e...

Embodiment 2

[0030] In the 5000Kg Bohai Nanpu 35-2 oilfield production sewage, after measuring the calcium and magnesium ion content in the sewage, add 2.42Kg of disodium edetate according to the molar ratio of the complexing agent to the sum of calcium and magnesium ions 1:1 As preparation water.

[0031] Add 105Kg of sorbitan stearate to 3500Kg Nanbao 35-2 oilfield heavy oil, mix well, then slowly add 1500Kg of preparation water, and keep stirring during the water addition process, stir for 20 minutes, and make 5105Kg of water 29.4% W / O emulsion.

[0032] Add 70Kg sodium dodecyl carboxylate to 3400Kg preparation water, mix well; add 5105Kg W / O type emulsion prepared into it, stir for 10 minutes, and make 8575Kg W / O / W type thick oil plug agent.

Embodiment 3

[0034] Take the sewage produced by the J platform of Suizhong 36-1 oilfield in Bohai Sea, and measure the sum of calcium and magnesium ions in the sewage to be 420mg / L. Add 4515mg / L disodium ethylenediaminetetraacetic acid to complex calcium and magnesium ions in water.

[0035] Add 5wt% sorbitan fatty acid esters to the heavy oil produced at the J platform of Suizhong 36-1 oilfield in Bohai Sea, mix well, then slowly add 50wt% water for preparation of the heavy oil weight, and keep stirring during the water addition process, Stir for 50 minutes to prepare a W / O emulsion containing 40 wt% of internal phase water.

[0036] Add 3wt% sodium lauryl fatty acid sodium lauryl fatty acid to the prepared water after treatment, mix well and use it as external phase preparation water; add the prepared W / O emulsion containing internal phase water into the prepared external phase preparation water, and prepare the external phase preparation water The weight of water is 100% of the weight ...