公开(公告)号：US20200300082A1

公开(公告)日：2020-09-24

申请号：US16899546

申请日：2020-06-11

Applicant: SOUTHWEST PETROLEUM UNIVERSITY ,  PETROCHINA COMPANY LIMITED

Inventor： Pingli Liu ,  Xiang Chen ,  Heng Xue ,  Honglan Zou ,  Liqiang Zhao ,  Nianyin Li ,  Daocheng Wang ,  Zhifeng Luo ,  Juan Du ,  Chong Liang ,  Mingyue Cui ,  Fei Liu ,  Changlin Zhou ,  Rong Zeng

IPC: E21B47/10 ,  E21B43/27 ,  G06F30/28 ,  G06F17/11

Abstract: The invention discloses a calculation method for dynamic fluid loss of acid-etched fracture considering wormhole propagation, which is applied to pad acid fracturing process, comprising the following steps: Step 1: dividing the construction time T of injecting acid fluid into artificial fracture into m time nodes at equal intervals, then the time step Δt=T/m and tn=nΔt, where, n=0, 1, 2, 3, . . . , m, and to is the initial time; Step 2: calculating the fluid loss velocity vl(0) in the fracture at t0; Step 3: calculating the flowing pressure distribution P(n) in the fracture at tn; Step 4: calculating the width wa(n) of acid-etched fracture at tn; Step 5: calculating the wormhole propagation and the fluid loss velocity vl(n) at tn; Step 6: substituting the fluid loss velocity vl(n) into Step 3, and repeating Step 3 to Step 6 in turn until the end of acid fluid injection.

公开(公告)号：US10364388B2

公开(公告)日：2019-07-30

申请号：US15775009

申请日：2016-09-20

Applicant: SOUTHWEST PETROLEUM UNIVERSITY

Inventor： Liqiang Zhao ,  Yong Yang ,  Guangyan Du ,  Donghe Yu ,  Juan Du ,  Hang Che ,  Zhifeng Luo ,  Guohua Liu ,  Yuxin Pei ,  Nianyin Li ,  Pingli Liu ,  Kun Xu

IPC: C09K8/64 ,  C09K8/80 ,  E21B43/26 ,  C09K8/68 ,  C09K8/88

Abstract: The present invention discloses a phase change fracturing fluid system for phase change fracturing, including the following components in percentage by weight: 10%-40% of supramolecular construction unit, 0-40% of supramolecular function unit, 0.5%-2% of surfactant, 0-5% of inorganic salt, 0.5%-2% of oxidizing agent, 0-2% of cosolvent and the remaining of solvent. The supramolecular construction unit is melamine, triallyl isocyanurate, or a mixture thereof. The supramolecular function unit is vinyl acetate, acrylonitrile, or a mixture thereof. The solvent is methylbenzene, ethylbenzene, o-xylene, m-xylene or p-xylene. In the fracturing construction process, a conventional fracturing fluid is used for fracturing a formation first; the phase change fracturing fluid is then injected into the formation, or the phase change fracturing fluid and other fluids which cannot be subjected to phase change are injected into the formation together.

公开(公告)号：US10301919B2

公开(公告)日：2019-05-28

申请号：US15775384

申请日：2016-09-20

Applicant: SOUTHWEST PETROLEUM UNIVERSITY ,  PETROCHINA HUABEI OILFIELD COMPANY

Inventor： Liqiang Zhao ,  Yong Yang ,  Zhifeng Luo ,  Donghe Yu ,  Juan Du ,  Guohua Liu ,  Hang Che ,  Guangyan Du ,  Yuxin Pei ,  Nianyin Li ,  Pingli Liu ,  Kun Xu ,  Bingxiao Liu

IPC: E21B43/26 ,  C09K8/60 ,  C09K8/66 ,  C09K8/68 ,  C09K8/70

Abstract: A phase-change hydraulic fracturing process, including the following steps: (1) injecting clean water or conventional fracturing fluid to a formation, so that the formation fractures; (2) placing non-phase-change liquid and phase-change liquid in different liquid mixing tanks and injecting into a shaft at the same time, an injection volume ratio of the non-phase-change liquid to the phase-change liquid is (0-0.7):(0.3-1); (3) injecting a displacement fluid into the shaft, so that the non-phase-change liquid and the phase-change liquid in the shaft completely enter a reservoir; (4) performing well shut-in and pressure-out for 30-200 min, so that solid-phase matters generated by the phase-change liquid are laid in the fracture; and (5) relieving pressure to finish the construction.

公开(公告)号：US11781062B1

公开(公告)日：2023-10-10

申请号：US17844731

申请日：2022-06-21

Applicant: Southwest Petroleum University ,  Tianjin Branch of CNOOC (China) Co., Ltd

Inventor： Pingli Liu ,  Jun Li ,  Jian Yang ,  Jianfa Wu ,  Shang Gao ,  Xingwu Guo ,  Jian Zou ,  Xitang Lan ,  Liping Zhang ,  Zhifeng Luo ,  Lan Ren ,  Changlong Liu ,  Juan Du ,  Xiang Chen ,  Nianyin Li ,  Peng Wang

IPC: C09K8/80 ,  C09K8/60 ,  C09K8/68

CPC classification number: C09K8/80 ,  C09K8/605 ,  C09K8/608 ,  C09K8/68 ,  C09K2208/08 ,  C09K2208/10 ,  C09K2208/28

Abstract: The present invention relates to a bionics-based efficiently transported and packed proppant and preparation method thereof, comprising enhanced fracturing fluid and biomimetic dandelion proppant; the mass ratio of the enhanced fracturing fluid and the biomimetic dandelion is: 1-2:100-400; the 100 pbw of enhanced fracturing fluid includes 0.1-1 pbw of drag reducing agent, 0.01-0.1 pbw of cleanup additive, 0.2-0.8 pbw of clay stabilizer, 0.01-0.05 pbw of bactericide, 0.01-0.2 pbw of nanoparticle enhancer, and water; the biomimetic dandelion proppant consists of modified proppant and modified fiber, and the mass ratio between the modified proppant and the modified fiber is 99-99.9:0.1-1.

公开(公告)号：US11174425B2

公开(公告)日：2021-11-16

申请号：US16910807

申请日：2020-06-24

Applicant: SOUTHWEST PETROLEUM UNIVERSITY

Inventor： Weiyu Chen ,  Liqiang Zhao ,  Zhifeng Luo ,  Juan Du ,  Pingli Liu ,  Nianyin Li ,  Kun Xu

IPC: E21B21/08 ,  C09K8/76 ,  C09K8/68 ,  C09K8/72 ,  C09K8/92

Abstract: The present invention relates to a carbonate reservoir filtration-loss self-reducing acid fracturing method. The carbonate reservoir filtration-loss self-reducing acid fracturing method comprises the steps: (1) calculating a fracture pressure and a fracture extension pressure of a reconstructed reservoir; (2) injecting an agent A into a stratum under a pressure higher than the stratum fracture pressure, so that fractures are generated on the stratum; (3) injecting an agent B into the stratum under a pressure higher than the stratum fracture pressure, such that the agent B extends the fractures and communicates with a natural fracture net; (4) pumping an acid liquor system agent C with a high etching power into the stratum under a pressure higher than the extension pressure but lower than the fracture pressure to improve the conductivity of the fractures; (5) injecting a displacing liquid agent D under a pressure lower than the stratum fracture pressure to jack acid liquor in a well casing into the stratum; and (6) shutting down a well and performing flow-back. The agent A is a gel acid or VES acid, the agent B is a filtration-loss self-reducing gel acid or filtration-loss self-reducing VES acid, the agent C is closed acid, and the agent D is a displacing liquid. According to the method of the present invention, precipitation type solid filter cakes are formed on wall surfaces of the fractures by utilizing a filtration-loss self-reducing system, so as to perform temporary blocking to reduce the filtration loss. The technology is simple with easy injection, and the filtration-reducing agent is easy to disperse and flow back, and the method is safe and environment-friendly.