R & D On The Main Completion String Of Horizontal Well Segregated Fracturing

Segregated fracturing of horizontal well is an effective transformation of horizontal wells on reasonable utilization of low permeability reservoir.Segregated fracturing completion can complete a multiple reservoir fracturing one time in a short period,accomplishing commingling.And is one of the key parts of horizontal wells supporting technology.The applications of horizontal well segregated fracturing technology can minimize the damage on formation.Now,horizontal well segregated fracturing technology mainly includes:coiled tubing separate layer fracturing technology,the open hole segregated fracturing of horizontal wells(including the acid fracturing)technology,etc.For low permeability reservoirs,the natural production capacity of horizontal well is low,and screen completion is applied for most of the horizontal well,the well length is about several hundred meters,segregated fracturing can not be achieved effectively then,making more horizontal wells low-yielding and inefficient,making hardly to get the ideal development effect.Reservoir geological conditions and the length of the well section restrain the wider deployment of low permeability horizontal wells.Therefore,R&D on the main completion string of horizontal well segregated fracturing has a very important significance.In this paper,horizontal well fracturing and acidizing process at home and abroad were analyzed and various completion programs were screened to determine the overall design scheme of the main completion string of horizontal well segregated fracturing:first the helical shaper is applied to settle the open hole well section and the well diameter.making the well section meet the requirements of the tripping in of the open hole packer,and then completion fracturing technology string should be tripped in following the string design,pressuring after inputting the end circulation valve ball,completing the hanger sitting and the initial sitting of the open hole packer,releasing the hanger according to the operation requirement,and pulling out the string above the hanger;tripping in stinger using the fracturing tubing,and forcing the tubing after tripping stinger in the liner hanger core tube assembly,opening the pressure differential scale sleeve and accomplishing the final sitting of the open hole packer,the first fracturing construction renovation can be conducted;after the first fracturing construction,dropping successively according to fracturing construction design;and after all of the fracturing construction,blocking ball at different levels would be discharged out of the well bore along with the flow back fluid,then according to the production design,production string is tripped in to sum layer production.In this paper,the main completion string of horizontal well segregated fracturing is completed consisting of the centering guide,drilling liner hanger,insert core tube assembly,open hole packer,fracturing sand blower,differential pressure sliding sleeve,and end circulating valve,etc.through the structural design of the main completion string of horizontal well segregated fracturing,the development of the open hole packer sealant tube,the Packing block ball with low density and high strength,well spiral shaper and a complete set of techniques of the main string,and plentiful laboratory test.The key point of this study lies in the research and development of the sealant tube and low-density ball sealers.Meanwhile,the overall design of the entire string must be precise enough to ensure the successfully rise and down,to overcome the possible exceptions of the borehole.Either,the performance of various components including the casing hanger,sand blower,multi-stage sliding sleeve,and the end circulating valve need to meet requirements of overall strings.