Abstract: The disclosure provides an optical imaging lens assembly, which sequentially includes from an object side to an image side along an optical axis: a first lens with a positive refractive power; a second lens with a refractive power; a third lens with a refractive power; a fourth lens with a refractive power; a fifth lens with a refractive power, an object-side surface thereof is a convex surface, and an image-side surface thereof is a concave surface; a sixth lens with a positive refractive power, an object-side surface thereof is a convex surface, and an image-side surface thereof is a concave surface; a seventh lens with a negative refractive power; wherein an on-axis distance TTL from an object-side surface of the first lens to an imaging surface and a half of a diagonal length ImgH of an effective pixel region on the imaging surface satisfy: TTL/ImgH<1.25.

Abstract: The present disclosure relates to a method and a device for predicting ability of a temporary plugging agent to plug cracks and a storage medium, and includes the following steps: calculating a plane elastic modulus of a core through experiments, acquiring a maximum force load of a specimen, calculating rock fracture toughness through the maximum force load, manufacturing an artificial crack model and placing it in a core holder, preparing temporary plugging deflection fluid by selecting a temporary plugging agent, injecting the temporary plugging deflection fluid into the artificial crack so as to calculate apparent fracture toughness of the temporarily plugged crack, and finally calculating a fracture pressure of the temporarily plugged crack based on the calculated rock fracture toughness and the plane elastic modulus of the core. Through the above method, the present disclosure provides a standard fracture pressure calculation method.

Abstract: A camera lens group including, sequentially from an object side to an image side along an optical axis, a first lens having negative refractive power, a concave object-side surface and a concave image-side surface; a second lens having refractive power, a convex object-side surface and a concave image-side surface; a third lens having positive refractive power, a convex object-side surface and a convex image-side surface; a fourth lens having refractive power; a fifth lens having positive refractive power and a convex image-side surface; and a sixth lens having negative refractive power, a convex object-side surface and a concave image-side surface. Half of a field-of-view Semi-FOV of the camera lens group and half of a diagonal length ImgH of an effective pixel area on an imaging plane satisfy: 10.00 mm<tan2(Semi-FOV)*ImgH<23.50 mm. A maximum distortion of the camera lens group is less than 3.50%.

Abstract: A nano-emulsion composition having a small particle size and ultra-low concentration and a preparation method thereof is disclosed. The raw materials of the composition comprise, in terms of percentage by weight, 0.002% to 0.2% of a polymer-containing homogeneous microemulsion, water, and 99.998% to 99.8% of an organic salt solution or inorganic salt solution. The composition is prepared by diluting a polymer-containing homogeneous microemulsion with water or a salt solution. The polymer-containing homogeneous microemulsion is formed by mixing the following raw materials, in terms of percentage by weight: 8% to 40% of a surfactant, 0.5% to 10% of a polymer, 10% to 30% of an alcohol, 3% to 30% of an oil, 0% to 20% of a salt, and balance of water. The composition of the invention is low in concentration, low in cost, narrow in particle size distribution, good in stability, simple in preparation, and convenient for storage and use.

Abstract: A nano-emulsion composition having a small particle size and ultra-low concentration and a preparation method thereof is disclosed. The raw materials of the composition comprise, in terms of percentage by weight, 0.002% to 0.2% of a polymer-containing homogeneous microemulsion, water, and 99.998% to 99.8% of an organic salt solution or inorganic salt solution. The composition is prepared by diluting a polymer-containing homogeneous microemulsion with water or a salt solution. The polymer-containing homogeneous microemulsion is formed by mixing the following raw materials, in terms of percentage by weight: 8% to 40% of a surfactant, 0.5% to 10% of a polymer, 10% to 30% of an alcohol, 3% to 30% of an oil, 0% to 20% of a salt, and balance of water. The composition of the invention is low in concentration, low in cost, narrow in particle size distribution, good in stability, simple in preparation, and convenient for storage and use.

Abstract: A synthesis method for degradable material(s) (DM) which can be used in oil and gas field operations. The method involves using two, three, four or five polymer and chain extenders, including poly glycolic acid (PGA), polycaprolactone (PCL), polylactic acid (PLA), poly (butylene succinate) (PBS) and poly(3-hydroxybutyrate) (PHA), to synthesize a “resin alloy” through the melt mixing reaction method, which can be used in oil and gas field operations. The proposed DM can be prepared into flake, powder, granules, and ball shapes, or by one of the pure PGA, PCL, PLA, PBS and PHA, into flake, powder, granule and ball shapes, which can be further used in all kinds of operations (drilling, well completion, workover and acidizing fracturing) in oil and gas fields, such as temporary plugging to protect a reservoir, temporary plugging of perforation holes, construction intervals, etc. The DMs are fully degradable and cause almost no damage to formations.

Abstract: A synthesis method for degradable material(s) (DM) which can be used in oil and gas field operations. The method involves using two, three, four or five polymer and chain extenders, including poly glycolic acid (PGA), polycaprolactone (PCL), polylactic acid (PLA), poly (butylene succinate) (PBS) and poly(3-hydroxybutyrate) (PHA), to synthesize a “resin alloy” through the melt mixing reaction method, which can be used in oil and gas field operations. The proposed DM can be prepared into flake, powder, granules, and ball shapes, or by one of the pure PGA, PCL, PLA, PBS and PHA, into flake, powder, granule and ball shapes, which can be further used in all kinds of operations (drilling, well completion, workover and acidizing fracturing) in oil and gas fields, such as temporary plugging to protect a reservoir, temporary plugging of perforation holes, construction intervals, etc. The DMs are fully degradable and cause almost no damage to formations.