Exploration of ultra high strength sand fracturing technology for shale gas in Yongchuan north district
The northern area of Yongchuan shale gasfield is located in Chongqing,the de-velopment layer is composed of the silurian Wufeng formation-Longmaxi formation,buried at a depth of about 4 100 m,currently in the development evaluation stage.The reservoir has high stress,high fracture pressure,high closure pressure,and low degree of natural crack de-velopment,faced with difficulties in forming complex artificial fracture networks,difficulty in adding sand,and difficulty in maintaining high diversion capacity.This article studies the transportation mechanism of proppants and clarifies that the particle size,liquid viscosity,and construction displacement of proppants are important factors affecting the difficulty of sand addition.Corresponding technical measures for ultra high strength sand fracturing are proposed.Applied to the horizontal well YY2-2,the maximum sand addition strength of a single section is 7.70 t/m,and the average is 5.82 t/m,the comprehensive sand ratio is in-creased to 10.2%.The post fracturing evaluation shows that the ultra high strength sand frac-turing technology has significantly improved the volume of transformation and the complexity of artificial fractures,and the initial trial production effect is far superior to the well imple-mentation in the early stage.This provides support for the construction of production capaci-ty in the north district of Yongchuan,and also provides technical references for the effective development of similar deep shale gas.
shale gassand addition strengthdifficulty of sand additionultra high strengthhorizontal well
NETL
NSTL
万方数据
维普
