Research And Application Of Fiber-complex Fine-silty Sand Control Technique In The Unconsolidated Sand Reservoirs

Sand control is the most difficult issue faced by operation of the unconsolidated sand reservoirs. Traditional sand control techniques not only are ineffective to fine-silty sand control but also have great impact on the productivity of oil/gas wells. Fiber-resin coated sand control technique is put forward as a new technique for fine-silty sand control in the unconsolidated sand reservoirs, achieving both without sand production and oil/gas production stimulation purposes on the basis of new sand control theory of "clean pollution", "stabling ambulatory sands", "fixing sands", "barring fine-silty sand congeries", "protection reservoir" and "increase production". Based on the research of Gudao Oilfield's sand production mechanism and lots of experiments, this research has developed a special sand control fiber and did the evaluation of the fiber, such as the impact of acid, alkali, salt and temperature. Series fiber-complex sand control techniques were developed. Studies were done on the various factors, such as the length and diameter of the fiber, proppant size, ect, impact on the fiber's ability in fixing the sand body. The mechanism of the sand control techniques has been analyzed and complete evaluation system has been established. The core of the techniques can be summarized as: (l)special fiber and fiber-complex; and (2) the fiber-complex sand control operation technique. The fiber-complex sand control achieves sand control by embracing "clean pollution", "stabilization of sand", "fixing sand", "prevention", "protection reservoir" and "increase production" techniques. The "clean pollution" means clearing the well nearby pollution and obstacles by using organic acids or fracturing techniques; "stabilization of sand" is by using positive charged long branch polymer to adhere fine-silty sands to stabilize the sands; special sand control fiber can form a 3-dimensional reticular structure to "fix resin-coated sands" and form a like kind screen pipe. The screen pipe like packing formed near the well and in the fracture can "prevent" the fine-silty sands to flow into the production well; the zero damage clear fracturing fluid can "protect reservoir" and its permeability and finally the TSO technique can "increase production" for a great deal. Fiber-resin coated sand control technique has been successfully used in 28 wells' sand control in Gudao and Xianhe Oil Production Plant in Shengli Oilfield, Sebei Gas Field, and Xinjiang Oilfield. The technique is simple to operate, effective in sand control. High-pressure pack fiber-resin coated sand control in 5 production/injection wells have been performed and with 1:4.5 cost/benefit ratio, and its period of validity is long. This technique provides strong technique support for the unconsolidated fine-silty sand reservoirs.