Southwest Petroleum University

Chengdu Leps Technology Co., Ltd

Jichuan Ren

Jianchun Guo

Bo Gou

Chi Chen

Jie Lai

Bin Liu

Cong Lu

Bo Yang

Shan Ren

Kun Wang

Gang Li

Tao Zhang

Xiao Li

Shaobin Zhang

Qingsong Guo

Yang Lu

Shouxin Wang

Mingyuan Zhou

Xinghao Gou

Xiang Bai

Hao Ou

Yangyi Xing

The present disclosure provides a high-temperature-resistant deep penetration molecular membrane acid copolymer and a preparation method thereof. The copolymer is formed by polymerizing four raw monomers including 2-acrylamido-2-methylpropanesulphonic acid, vinyl phosphonic acid, alkyl dimethylallyl ammonium chloride, and perfluoropolyether acrylate. The method comprises: S1: mixing and stirring solvent oil, an emulsifier, the alkyl dimethyl allyl ammonium chloride, and the perfluoropolyether acrylate to be dispersed homogeneously to obtain an oil phase; S2: mixing and stirring the 2-acrylamido-2-methylpropanesulphonic acid, the vinyl phosphonic acid, a complexing agent, and distilled water, and adjusting pH to obtain an aqueous phase; S3: slowly dropwise adding the aqueous phase to the oil phase; and S4: introducing nitrogen into the water-in-oil emulsion to remove oxygen, then adding an initiator and carrying out a heating polymerization reaction to obtain copolymer emulsion (i.e., a molecular membrane agent). The copolymer emulsion is added to an acid solution to obtain molecular membrane acid.

High-temperature-resistant deep penetration molecular membrane acid copolymers and preparation methods thereof

The present invention discloses a novel high-temperature visual acid etching test device and method; the test device includes a visual rock slab holder, an acid solution storage tank I, an acid solution storage tank II, a heating apparatus, a high-pressure water pump, a low-pressure acid pump, a back-pressure valve, an acid valve A, an acid valve B, an acid valve C, an acid valve D, an acid valve E, an acid valve F, a water valve G, a water valve H, a water valve I, a water valve J, and a water valve K; both the acid solution storage tank I and the acid solution storage tank II are provided with a piston therein, where the acid solution storage tank is divided into upper and lower independent parts by the piston. According to the present invention, the flowing process of an acid solution in a fracture can be directly observed to accurately characterize the distribution of the acid solution in the fracture, which facilitates a study on an acid etching mechanism. According to the present invention, an acid solution injection system is separated from a water injection system, so that only water is injected into the system through a high-pressure pump, effectively solving safety problems of acid solution pumping. In the test process of the present invention, a totally-enclosed acid solution system can ensure that the acid solution does not overflow at high temperature and high pressure, thus greatly increasing the safety of the test.

High-temperature visual acid etching experimental device and method

The invention introduces a method of calculating etching profile of acid-etched fracture system considering complex filtration media, which mainly considers dynamic filtration caused by natural fractures and acid-etched wormholes in acid fracturing, calculates the above filtration process by a numerical method, and finally calculates acid etching profile of acid-etched fracture system based on acid concentration profile. Calculation equations include fluid pressure in natural fractures, filtration velocity in natural fractures, fracture geometry of hydraulic fractures, fluid pressure in matrix rock, acid concentration profile in natural fractures and hydraulic fractures, acid etching width in hydraulic fractures and natural fractures, and length of acid-etched wormhole, etc. The invention is reliable in principle and efficient in calculation, which is also beneficial to accurately calculating fracture etching profiles of acid fracturing in naturally-fractured reservoirs, improving the accuracy of optimizing acid fracturing treatment parameters, and providing guiding significance for acid fracturing optimization of naturally-fractured carbonate reservoirs.

Method of calculating etching profile of acid-etched fracture system considering complex filtration media

The present invention discloses a method for experimentally determining the conductivity distribution of an acid-fractured fracture a carbonate rock oil and gas reservoir, including the following steps: by an acid fracturing simulator FracproPT, simulating and acquiring distribution data of fracture width, fracture height, temperature and acid liquor mass concentration in a hydraulic fracture length direction; selecting fracture width, fracture height and temperature data of total 10 feature points with the acid liquor mass concentrations being from 100% to 10% of the initial mass concentration; converting site acid injection displacement into laboratory acid injection displacement; preparing experimental acid liquor according to the acid liquor mass concentration data of the 10 feature points; and simulating the acid etching process, and experimentally testing the conductivity under the condition of reservoir closed pressure, and drawing a distribution diagram of the acid-etched fracture conductivity in the fracture length direction under the reservoir condition.

Method for experimentally determining conductivity distribution of acid-fractured fracture of carbonate rock oil and gas reservoir

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Chengdu, China

Jichuan Ren