Reasearch On The Mechanism Of Annular Channeling During Horizontal Multi-stage Fracturing

Multi stage fracturing of horizontal wells is a kind of can significantly improve the lowporosity, reservoir transformation measures yield tight sandstone reservoir with lowpermeability, has been widely used in various fields. Multi stage fracturing of horizontal wellsfracturing construction, ensure that each segment is not channeling is the successfultransformation of the reservoir, essential prerequisite to improve the fracturing effect. Andbecause the cementing quality in the horizontal wells, influence of cement strength andfracturing process parameters, the fracturing during construction of channeling segment,reduce the fracturing effect.This paper analysis the influence factors of channeling multi-stage fracturing horizontalwell between the flow mechanism, through the study of cement sheath body and cementinginterface channeling flow, whether or not the multi-stage fracturing horizontal well theoccurrence of channeling. The research contents in this paper are as follows: the influence onthe quality of well cementing and fracturing parameters on the fracturing fluid channeling;study established cement mechanical model of fracturing and mechanical evaluationofperforation on the cement sheath collapse strength and impact strength of anti pressure withinthe model takes into account; build fracturing adjacent segments of cement mechanical model;according to the elastic mechanics and fracture mechanics theory established the calculationmodel of the horizontal well cementing interface failure length; from the cement loop damage,two cementing interface of two party damage to the scene of a well section of cross flow typediscrimination, have horizontal multi-stage fracturing cause channeling is fracturing fluidpressure cement sheath and the formation bonding interface crack, crack length is greater thanthe perforation spacing channeling.This paper provides an important theoretical basis for the research of this thesis is themulti stage fracturing of horizontal wells when the annular flow type judgments, is of greatsignificance to the rational choice of fracturing fluid construction parameters of multi stagefracturing of horizontal wells to prevent annular flow.