Composite fast-hardening silicate leakage stopping slurry and leakage stopping method thereof

Abstract

The invention provides composite fast-hardening silicate leakage stopping slurry and a leakage stopping method thereof. The silicate leakage stopping slurry comprises a main agent and a curing agent, a volume ratio of the main agent to the curing agent is 5:1, and the main agent and the curing agent are mixed to form solid gel. Industrial sodium silicate serving as the main agent and organic ester serving as the gel delay curing agent to form the solid gel under an alkaline condition to realize leakage stopping, water repellency of a leakage stopping system is improved, strength of a leakage stopping layer is improved, mixed alternation of formation water and the leakage stopping slurry can be effectively inhibited, gradual enhancement along with time after injection of the slurry into a leak layer is kept, pressure bearing capacity of the leak layer is improved, the problem of leakage of loss return type absorption wells is solved, one-time leakage stopping success rate is increased and exceeds 50%.

Description

technical field [0001] The invention relates to the technical field of petroleum drilling, in particular to a composite quick-setting silicate plugging slurry and a plugging method thereof, which are suitable for fractured leakage in the Luohe Formation in the Longdong block. Background technique [0002] The buried depth of the Jurassic Luohe Formation in Changqing Xifeng Oilfield is 700-1100m, the underground temperature is between 28-35°C, and vertical and horizontal fractures are developed. The water is relatively active, and conventional bridge plugging, cement slurry plugging, etc. are easily diluted and dissolved by formation water, and the plugging effect is poor, time-consuming and material-consuming, affecting the construction progress, and the one-time success rate of plugging is less than 50%. : [0003] 1. The rigidity of the plugging material is insufficient [0004] All the bridge plugging materials currently used cannot reach the solidified rigidity of conc...

AI Technical Summary

Problems solved by technology

[0002] The buried depth of the Jurassic Luohe Formation in Changqing Xifeng Oilfield is 700-1100m, the underground temperature is between 28-35°C, and vertical and horizontal fractures are developed. The water is relatively active, and conventional bridge plugging, cement slurry plugging, etc. are easily diluted and dissolved by formation water, and the plugging effect is poor, time-consuming and material-consuming, affecting the construction progress, and the one-time success rate of plugging is less than 50%. :

[0003] 1. The rigidity of the plugging material is insufficient

[0004] All the bridge plugging materials currently used cannot reach the solidified rigidity of concrete, and are almost ineffective for large cracks or extra-large malignancies;

[0005] 2. Existing plugging materials lack adhesion to rocks and have insufficient hydraulic erosion resistance

[0007] 3. Insufficient rigidity and strength of gel plugging

[0008] Although chemical gel has many advantages, such as: better pumpability, delayed crosslinking, late gelation, water repellency, rock adhesion, overall tensile capacity (tension) and compressive capacity (elasticity), etc., but the lack of congenital composition (solid content <10%) restricts the performance of its overall comprehensive rigidity;

[0009] 4. Defects of cement injection plugging process

[0011] ②The cured cement plug layer has only rigid strength, and lacks "flexibility" under the action of mechanical stress, and may be fractured again by the exciting pressure of the drilling fluid in the wellbore