Southwest Petroleum University

Lin Sun

Rui Liu

Wanfen Pu

Daijun Du

Shishi Pang

Fayang Jin

Xing Zhao

Ke Xing Li

Bo Ren

Xiang Li

Long He

Wei Liao

Bowen Chen

Desheng Qian

Shi Gao

Fa Yang Jin

Wan Fen Pu

Wen Ge Hu

Hai Yang Zhao

Dai Jun Du

Ye Ju

Bao Lei Jiao

Zhen Qian

En Long Zhen

Kexing Li

Xiao Qing He

Jianyong Xie

Binyang Zou

Shuyu Song

Yan Shi

Yanjie Chu

Yingxue Xu

Mian Wang

Huancai Fan

A tight oil reservoir COflooding multi-scale channeling control system and a preparation method, including nanoscale COresponsive worm-like micellar systems and micron-scale COresponsive dispersion gel, are provided. The nanoscale COresponsive worm-like micelle system is prepared by COreactive monomers and organic anti-ion monomers stirred in water. The micron-scale COresponsive dispersion gel is made of acrylamide, a responsive monomer, a silane coupling agent modified hydroxylated multi-walled carbon nanotubes as raw materials, cross-linked in water. The tight oil reservoir COmulti-scale channel control system, has strong flow control ability during COdisplacement, and high-strength carbon nanotubes are introduced into the micro-scale COresponsive dispersion gel, which effectively improves the strength and long-term stability of the dispersion gel, significantly enhances the sealing effect on cracks, and after displacement of the COof the system, the worm-like micelles revert to spherical micelles with good responsive reversibility.

Tight oil reservoir COflooding multi-scale channeling control system and preparation method

The present disclosure discloses methods for preparing an in-situ nano emulsifier. The preparation method may include obtaining a solution by dissolving hydrated ferric chloride (or ferric chloride) and hydrated ferrous sulfate (or ferrous sulfate) into deionized water at a first temperature; obtaining an ethanol solution dissolved with an oil-soluble surfactant by dissolving an oil-soluble surfactant into ethanol at a second temperature; and adding a certain volume of ammonia water and the ethanol solution dissolved with the oil-soluble surfactant in the solution to obtain an in-situ nano emulsifier. The in-situ nano emulsifier may be applied to development of the oil reservoir through an application process. The application process may include preparing a nano emulsifier solution and a surfactant solution; sequentially injecting the surfactant solution and the nano emulsifier solution into a formation; and injecting a spacer liquid slug into the formation for replacement.

Methods for preparing and applying a nano emulsifier

The present invention discloses a method for enhancing the recovery factor of heavy oil by in-situ oil-water emulsion with high phase inversion point, and the method is aimed at the development of heavy oil reservoir by water injection under the condition that the performance parameters of crude oil emulsion meet the following three specific requirements: (A) The viscosity of the crude oil is less than 6,000 mPa&#xb7;s; (B) At the reservoir temperature, the phase inversion point of the crude oil emulsion is greater than or equal to 70%, and the emulsion viscosity corresponding to the phase inversion point is 2-6 times of the crude oil viscosity; (C) At the reservoir temperature, when the water cut is less than or equal to the phase inversion point, the flow rate ratio of crude oil emulsion to crude oil is 0.2 to 0.9.

Method for enhancing the recovery factor of heavy oil by in-situ oil-water emulsion with high phase inversion point

The present invention discloses an in-situ emulsification and viscosity increase system with a high phase change point. The system consists of the following components in percentage by weight: 0.2&#x2dc;0.5% of water-soluble surfactant, 0.2&#x2dc;1.5% of oil-soluble surfactant, 0.02&#x2dc;0.5% of lipophilic colloidal particles, 0.02&#x2dc;0.2% of carrying agent and the balance of mineralized water. The water-soluble surfactant is one of or a combination of petroleum sulfonate, cocamidopropyl betaine, fatty alcohol ether sulfonate, alkanolamide and alkyl glycoside; the oil-soluble surfactant is one of or a combination of propylene glycol monostearate, fatty glyceride, polyoxyethylene sorbitan monostearate, polyoxyethylene fatty alcohol ether, oleic diethanolamide, dodecylamine, octadecyl primary amine, sodium oleate and petroleum acid; the lipophilic colloidal particles are one of liquid paraffin, graphite powder and polyhedral oligomeric silsesquioxane; the carrying agent is one of carboxymethyl-&#x3b2;-cyclodextrin, chitosan quaternary ammonium salt, chitosan hydrochloride, xanthan gum and guar gum. The system is used for water-flooding oil reservoirs and can significantly improve the development effect of water-flooding heavy oil reservoirs.

In-situ emulsification and viscosity increase system with high phase change point and application thereof in water-flooding oil reservoir

An amphoteric two-dimensional nanosheet and a preparation method thereof are provided. The amphoteric two-dimensional nanosheet is prepared by the following steps: uniformly dispersing few-layered graphene oxide into toluene and then adding alkylamine coupling agent to a mixture of the few-layered graphite oxide and the toluene for reaction; amine terminated graphite oxide dispersion that has been prepared is fully dispersed in toluene-dimethylformamide mixed solvent, and then, alkyl glycidyl ether is added into the above solution for reaction, so as to obtain the amphoteric two-dimensional nanosheet. The amphoteric two-dimensional nanosheet of the present disclosure can be prepared by modifying two-dimensional graphite oxide, to spontaneously form water-in-oil Pickering emulsion at an oil-water interface, compared with emulsion of conventional surfactants, the present disclosure can effectively stabilize the waterflooding front, improve the sweep volume of waterflooding, have a simple synthesis process for convenient large-scale production, and be widely used in waterflooding development reservoirs.

Preparation method of amphoteric two-dimensional nanosheet

An in-situ emulsification and viscosity increase system with controllable viscosity consists of the following components in percentage by weight: 0.3&#x2dc;1.5% of emulsifier, 0.05&#x2dc;0.5% of ultrafine colloidal particles, 0.01&#x2dc;0.1% of suspending agent and the balance of mineralized water. The emulsifier is one of or a combination of petroleum sulfonate, petroleum carboxylate, sodium dodecyl sulfate, sodium dodecyl benzenesulfonate, alkyl glycoside, aliphatic alcohol ether carboxylate, aliphatic alcohol ether sulfonate, hydroxysulfobetaine and alkanolamide. The ultrafine colloidal particles are one of ultrafine silicon dioxide, ultrafine montmorillonoid, ultrafine ferric oxide, ultrafine ferroferric oxide, ultrafine aluminum oxide and ultrafine titanium dioxide. The suspending agent is one of partially hydrolyzed polyacrylamide, amylose, carboxymethyl chitosan, hydroxymethyl cellulose, xanthan gum and sodium alginate. The system is applicable to a water-flooding oil reservoir with the viscosity of lower than 50 mPa&#xb7;s, has a very broad coverage scope and outstanding economic benefits and can effectively promote efficient development of water-flooding oil reservoirs.

Insatiability emulsification and viscosity system with controlled viscosity and its application in water-driven reservoir

A particulate profile control agent self-adaptive to a size of formation pore throat and a preparation method thereof include: raw materials and mass fraction for preparing a system including a main agent of 0.04&#x2dc;0.2%, a nucleating agent of 0.005&#x2dc;0.01%, a crosslinking agent of 0.002&#x2dc;0.04%, an additive of 0.005&#x2dc;0.01% and water. The preparation method includes: adding the main agent in proportion to the water and evenly mixing the mixture of the main agent and the water, and then adding the additive, the crosslinking agent and the nucleating agent in turn so as to form the profile control agent; pumping the profile control agent into the formation to be reacted at a reservoir temperature for a period of time to form colloidal particles on the spot for sealing off a high-permeability layer. The present disclosure is of easy operation and low cost, low initial viscosity and good injectivity.

Particulate profile control agent self-adaptive to size of formation pore throat and preparation method thereof

A plugging agent with temperature-resistant, salt-resistant and high-expansion for plugging large fractures and a preparation method thereof of the present disclosure are provided, the plugging agent system consists of the following components: main agent: 6%&#x2dc;10%, cross-linking agent: 0.6%&#x2dc;1%, initiator: 0.006%&#x2dc;0.01%, additive: 6%&#x2dc;14%, and the rest being water; the preparation method includes the following steps: adding montmorillonite to water to prepare a montmorillonite dispersion system; adding the main agent, the cross-linking agent and the initiator to the montmorillonite dispersion system to prepare a main agent solution; putting the main agent solution into an oven with a temperature range with 90&#x2dc;20&#xb0; C. for 9&#x2dc;48 h to obtain gelation, the adhesive strength of the agent system can reach grade H, with 50&#x2dc;80 expansion multiple, good strength after being expanded and good water plugging effect under the condition of a temperature of 140&#xb0; C. and 250,000 degree of mineralization.

Plugging agent with temperature-resistant, salt-resistant and high-expansion for plugging large fractures and preparation method thereof

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Chengdu, China

Lin Sun