Southwest Petroleum University

Other

Yongming Li

Jinzhou Zhao

Xiyu Chen

Youshi Jiang

Yu Peng

Ang Luo

Qiang Ren

Pengjun Shi

Juhui Zhu

Bo Chen

Jiandu Ye

Liehui Zhang

Hu Jia

Yan Kou

Yitao Huang

Cheng Chang

Tai Chang

Wenjun Xu

Dingli Wang

Xia Dan

Linyao Yu

Wanfen Pu

Yijian Chen

Xiao Guo

Kun Wang

Zhenglan Li

Yubin Yang

Quantang Fang

Le He

Jingze Li

Pengfei Chen

Zixi Guo

Zhibin He

Jing Jia

Huohai Yang

Guowei Deng

Wang Tang

Lirui Zhong

Jingkai Hu

Huibo Wen

Fujian Liu

Shuxuan Li

Yibo Li

Zhibo Yu

Qing Yin

Dongyu Fu

Yadong Chen

Wenlian Xiao

Dingyuan Zhang

Manqing Qian

Jitian Ren

Haiyang Tang

Shuaishuai Liu

Lingli Zheng

The present disclosure relates to a method for evaluating a temporary plugging effect of fracturing in a low-permeability oil-gas reservoir based on monitoring pressure. The method comprises: calculating a wellbore friction resistance along a way from a wellhead to a target fracturing segment; calculating, based on a wellhead pressure monitored at the wellhead in real time, a wellbore pressure at the target fracturing segment; calculating a fluid pressure at a crack opening of each perforation cluster; calculating a perforation friction resistance coefficient of each perforation cluster; calculating a fracturing fluid instantaneous displacement of each perforation cluster; calculating, based on the fracturing fluid instantaneous displacement of each perforation cluster, a variation coefficient of a fracturing fluid displacement distribution after a fracturing construction is completed; and evaluating the temporary plugging effect of fracturing based on the variation coefficient.

Method for evaluating temporary plugging effect of fracturing in low-permeability oil-gas reservoir based on monitoring pressure

The embodiments of the present disclosure provide a method for diagnosing control effectiveness of a fracture height in hydraulic fracturing by combining monitoring a pressure signal, comprising: obtaining engineering data and geological data; calculating a fracture slit fluid pressure, a double-logarithmic slope of the fracture slit fluid pressure, and a bedding fracture pressure; updating a growth time of the fracture height and a reference pressure based on the fracture height in hydraulic fracturing; based on determining whether a fracturing construction operation ends, updating the cumulative fracturing time or calculating a ratio of the growth time of the fracture height to the total time of hydraulic fracturing.

Methods for diagnosing control effectiveness of fracture heights in hydraulic fracturing by combining monitoring pressure signals

The present invention discloses a double-crosslinked thermal phase transition gel temporary plugging agent and an application thereof, and relates to the technical field of oil and gas field development. The gel temporary plugging agent comprises the following components in percentage by weight: 5.8-18.3% of acrylic acid, 2.8-6.5% of 2-acrylamide-2-methylpropanesulfonic acid, 2.8-7.0% of hydroxyethyl acrylate, 0.2-1.0% of a degradable crosslinking agent, 0.4-1.2% of borax or boric acid, 0.2-0.8% of a high-temperature initiator, 2.6-4.5% of palygorskite attapulgite, 1.5-3.1% of a urea-formaldehyde resin, and the balance of water, wherein the gel temporary plugging agent is formed by underground gelation. The gel temporary plugging agent is applied to oil and gas reservoirs with a temperature of 100-150° C., can automatically be subjected to gelation and degradation, and has a low filtration loss before gelation.

Double-crosslinked thermal phase transition gel temporary plugging agent and application thereof

A method for predicting a risk of early screen-out in a near-well zone based on distributed fiber acoustic sensing (DAS) is provided. The method comprises: obtaining an acoustic signal during a fracturing process based on distributed optical fibers deployed in a well to be fractured, and obtaining pressure monitoring data based on at least one sensor deployed in the well to be fractured; determining, based on a location of a perforation cluster, and an acoustic signal of the perforation cluster, fracturing fluid flow velocity data of the perforation cluster by a first predetermined algorithm; determining, based on the fracturing fluid flow velocity data of the perforation cluster and perforation parameters of the perforation cluster, a perforation friction resistance pressure drop of the perforation cluster by a second predetermined algorithm; determining a near-well friction resistance pressure drop of the perforation cluster based on a fluid pressure, the perforation friction resistance pressure drop, a slit fluid pressure; determining a near-well friction resistance coefficient of the perforation cluster based on the near-well friction resistance pressure drop of the perforation cluster; and determining, based on the near-well friction resistance coefficient, whether the perforation cluster has the risk of early screen-out in the near-well zone.

Methods and systems for predicting risk of early-screen-out in near-well zone based on distributed fiber acoustic sensing (DAS)

The present invention relates to a low-shrinkage and high-strength plant-based resinous blocking agent and preparation method thereof, and belongs to the technical field of oilfield development. The resinous blocking agent consists of the following substances according to weight parts: 37.2˜47.8 parts of epoxy plant oil, 19.8˜37.2 parts of benzoxazine, 22.9˜31.6 parts of curing agents, 0.8˜1.8 parts of initiators, 1.2˜1.8 parts of toughening agents, 0.5˜1.2 parts of reinforcing agents, wherein the sum of the weight parts of the above substances is 100 parts, the epoxy plant oil is obtained through epoxidation on unsaturated carbon-carbon double bonds in a molecule of dehydrated plant oil; the benzoxazine is synthesized from long-chain diamine, monohydric plant phenol and paraformaldehyde. The blocking agent has the advantages such as high compressive strength, degradability, low shrinkage and excellent plugging performance, is easy to obtain cheap raw materials and controllable to a preparation process, can meet the requirements of oil-gas reservoirs for high-strength blocking agents, and has a broad market prospect.

Low-shrinkage and high-strength plant-based resinous blocking agent and preparation method thereof

The present invention discloses a plant-based self-degradable gel diverting agent and a preparation method therefor. The preparation method comprises the following steps: adjusting a pH of a formaldehyde solution, adding urea in three batches, heating and stirring, adding furfural in the process of adding a second batch of urea until a plant-based urea-formaldehyde resin is obtained through the reaction, completely dissolving starch in water, uniformly stirring to obtain a gelatinized starch solution, adding the plant-based urea-formaldehyde resin, adding a curing agent, and uniformly stirring, mixing and curing to obtain a product. The resin plugging agent is a liquid homogeneous system and has a low initial viscosity; the system is particle-free, can enter tiny slits; and the gel temporary plugging agent does not need to be added with a gel breaker at a temperature of 100-180° C., the temporary plugging agent can be completely degraded.

Plant-based self-degradable gel diverting agent and preparation method therefor

A supramolecular star-shaped polymer with β-CD as a core and a preparation method thereof. The supramolecular star-shaped polymer with β-CD as a core has a β-cyclodextrin-modified branched monomer F-β-CD that serves as a core and is grafted with acrylamide, acrylic acid, hydrophobic monomers and surface-active macromolecular monomers to form a supramolecular star-shaped polymer. The hydrophobic monomer is one or more of N-benzyl-N alkyl (meth) acrylamide and N-phenethyl-N alkyl (meth) acrylamide; the surface-active macromolecular monomer is one or more of allyl polyoxyethylene ether, alkylphenol polyoxyethylene ether (meth)acrylate, allyl alkylphenol polyoxyethylene ether, alkyl alcohol polyoxyethylene ether (meth)acrylate and allyl alkyl alcohol polyoxyethylene ether. The method has cheapness and easiness to obtain raw materials, ease to control synthesis conditions, and high yield. The present invention has excellent tackifying performance, temperature resistance, salt resistance and hydrolysis resistance, so that it shows good application prospects in the aspect of enhancing recovery ratios and hydraulic fracturing in oilfields.

Supramolecular star-shaped polymer with beta-CD as core and preparation method

An ultra-high temperature organic cross-linked fracturing fluid system consisting of the following components at mass percentages: 0.6 wt % of a supramolecular star-shaped polymer, 0.5-1.0 wt % of formaldehyde solution, 0.02-0.04 wt % of resorcinol, 0.05-0.2 wt % of an ammonium catalyst and the rest being water, wherein the supramolecular star-shaped polymer is a &#x3b2;-cyclodextrin-modified branched monomer F-&#x3b2;-CD that serves as a core and is grafted with acrylamide, acrylic acid, hydrophobic monomers and surface-active macromolecular monomers to form a supramolecular star-shaped polymer; the ammonium salt catalyst is one or more of ammonium chloride, ammonium bicarbonate, ammonium acetate, ammonium citrate, ammonium benzoate and ammonium oleate. The ultra-high temperature organic cross-linked fracturing fluid system uses a supramolecular star-shaped polymer as a thickener, an organic crosslinker as a crosslinker and an ammonium salt as a catalyst to form a fracturing fluid.

Ultra-high temperature organic cross-linked fracturing fluid system

An integrated wellhead device for filtering injected and produced gases is provided. The wellhead device comprises a horizontal tank body that is internally provided with an injected gas filtering system and a produced gas filtering system. The injected gas filtering system is internally provided with an oxygen removal chamber. A gas inlet of the injected gas filtering system is connected with an injected high-pressure gas source, and a gas outlet of the injected gas filtering system is connected with a gas injection well casing of Christmas tree. The produced gas filtering system is internally equipped with an oxygen removal chamber, a sulfur removal chamber and a carbon dioxide removal chamber. A gas inlet of the produced gas filtering system is connected with a gas production tubing of the Christmas tree, and a gas outlet of the produced gas filtering system is connected with a produced gas transmission pipe.

Integrated wellhead device for filtering injected and produced gases

The present invention discloses a method for realizing uniform stimulation for the oil and gas well by low-cost multi-stage fracturing, comprising the following steps: first calculate and predict the inlet widths of the fracture created in the planned hydraulic fracturing; then design the plugging scheme for blocking the fracture inlet after each fracturing treatment; the selected plugging particles are composed of filling particles and skeleton particles, with designed plugging scheme; after complete the design of plugging scheme, perform the fracturing treatment to create hydraulic fracturing in the reservoir; skeleton particles and filling particles are added into the fractures successively according to plan. The present invention provides a multi-stage single-cluster fracturing method, with the advantages of controllable fracture sizes and low cost. The present invention can realize a good uniformity of stimulation for the oil and gas wells.

Method for realizing uniform stimulation for the oil and gas well by low-cost multi-stage fracturing

The present invention discloses a method for evaluating fracture connectivity and optimizing fracture parameters based on complex network theory, comprising the following steps: obtaining natural fracture distribution laws and characteristic parameters of the formation based on previous knowledge of natural fractures in the formation and statistical analysis of fractures in the core, and establishing a discrete fracture network model of natural fractures based on the previous step; setting up hydraulic fractures, determining intersection relations in the fracture network and coordinates of intersection points of fractures: converting the actual fracture network into a complex network dual topology diagram based on complex network theory, and calculating evaluative indexes of the complex network to realize the evaluation of fracture network connectivity; changing the hydraulic fracture parameters to get the evaluation indexes of different hydraulic fracture schemes.

Method for evaluating fracture connectivity and optimizing fracture parameters based on complex network theory

A glass clamping model based on microscopic displacement experiment, including a frame, a transparent silicone sleeve having a horizontal through hole, a piston, a piston cap arranged on the frame, a connecting plate, a screw compression bracket, a clamp support, a glass sheet entirety placed in the transparent silicone sleeve, a boss, a light source and a microscope. The transparent silicone sleeve is sheathed on the piston cap, the piston penetrates through the horizontal penetration hole; the connecting plate and the clamp support are respectively connected to both ends of the frame, the end of the screw compression bracket is clamped between the frame and the connecting plate, and the piston and the frame are connected with the clamp support; an emptying channel and an inlet passage are respectively arranged at both ends of the piston, and an outlet passage is arranged at an end of the piston.

Glass clamping model based on microscopic displacement experiment and experimental method

The present invention discloses a testing device and evaluation method for sensitivity damage of core permeability tensor, comprising the following steps: first, obtain the cubic experimental rock samples and calculate the formation pressure distribution based on the reservoir geological data; then simulate the true stress and strain state of core in formation through triaxial stress loading, design the acid liquor, alkali liquor, inorganic salt solution, formation water and different displacement rates for displacement experiments, realize the determination of core three-directional permeability tensor under the same experimental conditions through three-directional sequential displacement, process the experimental data through Darcy's law, and calculate the damage degree of core permeability tensor under different sensitivity conditions of triaxial stress state; finally, identify the real-time flow state of fluid through permeability tensor synthesis, and realize the accurate and efficient testing and evaluation on permeability tensor sensitivity of reservoirs.

Testing device and evaluation method for sensitivity damage of core permeability tensor

The present invention discloses a method for comprehensive evaluation of shale fracability under the geology-engineering 'double-track' system, comprising the following steps: S1: Divide the target horizontal fracturing interval into multiple sampling sections; S2: Establish the reservoir property evaluation factor of each sampling section, and calculate the geological evaluation index of the target horizontal fracturing interval according to the reservoir property evaluation factor of each sampling section; S3: Establish the brittleness factor, natural fracture factor and natural fracture opening factor of each sampling section, and then establish the engineering evaluation index of each sampling section according to these factors; S4: Calculate the engineering evaluation index of the target horizontal fracturing interval according to the engineering evaluation factor of each sampling section; S5: Evaluate the fracability of the target horizontal fracturing interval according to the geological evaluation index and the engineering evaluation index.

Method for comprehensive evaluation of shale fracability under the geology-engineering 'double-track' system

The present invention discloses an optimized design method for a temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells, which comprises the following steps: calculating a particle size and a volume range of a candidate temporary blocking agent in an applicable target area; establishing a hydraulic fracture expansion calculation model with complete fluid-solid coupling; calculating an optimal average particle size required for effective temporary blocking; determining the particle size distribution of the temporarily blocked particles according to the optimal average particle size; calculating the particle volume of the temporary blocking agent required for effective temporary blocking; and predicting and evaluating a fracturing effect after the preferred temporary blocking design is adopted in the target area. The optimized design method for the temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells is used for improving the uniformity of fracture development of staged multi-cluster fracturing in horizontal wells, and has practicability and accuracy.

Optimized design method for temporary blocking agent to promote uniform expansion of fractures produced by fracturing in horizontal wells

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Chengdu, China

Yongming Li