Simulation Study On The Temporary Blocking Steering Value Of Carbonate Reservoir Fracturing In Tahe Oilfield

The Tahe fractured carbonate reservoir has the characteristics of extremely deep burial and strong heterogeneity.At the same time,the reservoir is also a typical high-temperature and high-pressure reservoir,and its reservoir space is mainly composed of cracks and caves.Fracturing technology is a commonly used reservoir reforming technique,but for the difficult-to-exploit,poor-quality carbonate reservoirs in the Tahe Oilfield which crack-controlled crude oil has been basically produced.Conventional fracturing is no longer sufficient for production needs.By repeating the technology of repeated fracturing and temporary turning,it is possible to re-open new cracks,increase the volume of use,communicate undeveloped reservoirs,improve oil recovery,and increase economic benefits.Based on the actual situation of Tahe Oilfield,this paper evaluates the feasibility of temporarily blocking steering fracturing in Ordovician carbonate reservoirs by numerical simulation.Based on fluid-solid coupling and fracture mechanics,a mathematical model of temporary blocking steering is established.In the numerical simulation software ABAQUS,temporary plugging is achieved by reducing the permeability at the temporary plugging and thus affecting the pressure distribution.The use of ABAQUS simulates two types of steering problems when considering natural cracks.Through the digital-analog simulation,the steering law of the crack near the wellbore under the action of the ground stress field is obtained.The deflection law after the crack intersects the temporary stress.When the crack has a certain angle with the maximum horizontal principal stress,the crack will be in the formation stress field.Steering under action,gradually deflecting and eventually extending along the direction of maximum horizontal principal stress.To study the effect of a single variable on the crack turning radius and the turning speed,the most important influencing factors are the horizontal ground stress difference and the angle of the natural crack.Large stress differences and small natural turing angles have small turing radius and small steering speeds.Through the study of crack steering and temporary blocking steering law,and aseries of parameters in the temporary blocking process,it can have certain guiding significance for the actual mining.