US 11,840,911 B2
Fracturing method with synergistic effects of energy enhancement, oil displacement, huff and puff, imbibition, and displacement
Pingtian Fan, Yan'an (CN); Weichu Yu, Yan'an (CN); Yuetian Liu, Yan'an (CN); Ping Li, Yan'an (CN); Yongdong Wang, Yan'an (CN); Baolin Guan, Yan'an (CN); Fengping Yan, Yan'an (CN); Yongtao Song, Yan'an (CN); Wenming Shu, Yan'an (CN); Aibin Wu, Yan'an (CN); and Min Sun, Yan'an (CN)
Assigned to Nanniwan Oil Production Plant, Yanchang Oilfield Co., Ltd., Yan'an (CN)
Filed by Nanniwan Oil Production Plant, Yanchang Oilfield Co., Ltd., Yan'an (CN)
Filed on Sep. 7, 2022, as Appl. No. 17/939,711.
Claims priority of application No. 202111569454.7 (CN), filed on Dec. 21, 2021.
Prior Publication US 2023/0193732 A1, Jun. 22, 2023
Int. Cl. E21B 43/26 (2006.01); E21B 43/267 (2006.01)
CPC E21B 43/26 (2013.01) 7 Claims
OG exemplary drawing
 
1. A fracturing method with synergistic effects of energy enhancement, oil displacement, huff and puff, imbibition, and displacement, comprising the following steps:
S1, selecting a well that has never been fracted as a fracturing well, obtaining reservoir parameters of the target layer of the fracturing well, and judging the compressibility of the reservoir according to the reservoir parameters;
S2, after determining that the reservoir can be compressible, dividing the target layer into several fracturing intervals;
S3, performing perforating operations on each fracturing interval of the fracturing well, so as to form cluster perforation in each fracturing interval;
S4, injecting pore cleaning fluid into the fracturing well to perform pore cleaning and acidizing pretreatment on each cluster perforation;
S5, designing fracturing construction parameters, wherein the fracturing construction parameters include at least pump rate, and the pump rate is higher than 10 m3/min;
S6, according to the fracturing construction parameters, alternately injecting slick water fracturing fluid and oil-displacement slick water fracturing fluid into each of the fracturing layers, respectively, wherein the oil-displacement slick water fracturing fluid is a slick water fracturing fluid added with an oil-displacement agent; at the same time, proppant is added intermittently between the slick water fracturing fluid and the oil-displacement slick water fracturing fluid, and particle size of the added proppant gradually increases, and the sand ratio of the fracturing fluid gradually increases, so as to realize fracture formation and sand filling;
wherein composition of the slick water fracturing fluid is: 0.1% of drag reducing agent, 0.2% of multifunctional additive, 0.05% of bactericide and 99.45% of water;
the oil-displacement slick water fracturing fluid is slick water containing 0.5% of biological oil-displacement agent;
the added proppants are respectively: 40/70 mesh quartz sand, 30/50 mesh quartz sand, and 20/40 mesh quartz sand according to the order of addition; and
the sand ratio of the fracturing fluid does not exceed 15%;
S7, after completion of the sand filling, injecting a displacement fluid into each of the fracturing intervals to inject the sand-carrying fluid in the wellbore into the fractures;
S8, soaking the well for a period of time, then opening the well for production.