Improvement And Application Of Separate Layer Fracturing Tool

The depth of oil and gas reservoir is more than3500meters in DongPu depression, these oil andgas reservoirs take considerable proportion in zhongyuan oilfield, and the feature is high temperature,high pressure, low porosity, low permeability and low natural productivity because of long perforatedinterval, skip distance, big layer difference. To enhance recovery and reserves producing degree of thedeep oil and gas reservoir, it is necessary to take separate layer fracturing measure for the layer. Moremature applies of separate layer fracturing technology tube are single packer separate layer tube andtechnology tube with two packers fracturing one layer in Downhole of Zhongyuan. They can completeone or two layers separate layer fracturing improvement with the help of packers and downholeauxiliary tools, but shortcoming is big packer releasing tonnage. The text analyses fully the shortcomingof separate layer fracturing tool and improves it to decrease packer releasing difficult and increase packerreleasing success rate of small workover derrick. The new hydraulic anchor and sand blower assemblycan decrease42.4%dropping sand height and63.6%dropping sand content by changing its position andstructure, so decrease influence dropping sand on packer releasing. The new packer with backingwashing circulation can drive backing washing circulation liquid to the bottom of the packers andbalance the pressure differences in oil pipe and casing pipe. the design can return smoothly the tube ofthe packers. Optimize high temperature and high pressure packer rubber. Series of separate layerseparate layer fracturing tools are designed, from one tube fracturing one or two target zones to one tubefracturing five target zones. By improvement the old technology tube and regular application, packerreleasing difficulties are decreased and packer releasing ratio of small workover derrick are improvedfrom70%to90%.