Fracturing Technology For Complex Lithology In Hailaer Basin

Hailaer basin is divided into three parts primarily as the Surennuoer, the Wuzhong region and the Beier depressed basin. Now some blocks have been put into production such as Su131, Su102, Bei301, Bei16, Bei28 and so on. From the boot to up the deposit layer is composed the Budate group, Xinanling group, Tongbomiao unit, Nantun unit, Damoguaihe unit and Yimin unit. Some complex lithology reservoirs with abundant oil such as water-sensitive formation, high nature fracture growing layers and some layers whose stress difference between the layer and the interlayer is not big enough to keep the fracture growing in the pay layer zone were found when fracturing the production wells and exploration wells. How to set the perfect fracture dimension and conductivities in the well location of the block is an very important question.Because of the jam in low sand ratio, the ratio of success is only 58% in complex lithology reservoirs of Hailaer basin. One reason is the losing of fluids was too much in Budate layer with much nature fracture. The other reason is water-sensitive formation was removable when the fluid passed by, another reason is the fracture grow into the interlayer and the height is too much and the width is too small that leads the lower ratio of the sand. To resolve the difficulties above-mentioned we have taken some measures. The first measure is forecasting to fracture parameters and evaluating based on the mini fracture. The second measure is setting the technique to identify characteristic parameters and interpret them. The third measure is controlling the fracture height based on the studying of mechanics of fracture pinnacle with a specifical mean of adjustable flux. The forth measure is the studying and the using of the special fracture fluid to cut down the harm to water-sensitive formation. Using these measures we have got a good result that the ratio of the fracturing operation ascend from 58.6% to 90%. And some wells have got a very high production, such as the well Bei302 got 135.52 ton oil per day, the well Su31 got 44.8 ton oil per day, and the well Bei28 got 46.59 ton oil per day. The success of fracturing operation offers technologic guarantee for oil production in Hailaer basin in time.