延时固化混纤维酚醛树脂覆膜砂LH-Ⅱ研制

Preparation of Fiber Admixtured Phenolic Resin Coated Sand as Sand Controlling Agent LH-Ⅱ with Delayed Curing Time

针对开发中后期疏松砂岩油藏的多产层出砂油井研制了防砂剂LH Ⅱ。用加有偶联剂的酚醛树脂制备覆膜砂 ,接质量比 10 0∶3与直径 1.2mm、长 8.0mm的聚酯纤维混合制成混纤维覆膜砂。该覆膜砂以油田污水或海水携带 ,充填入亏空油层 ,待各项井下作业完成后注入固化剂溶液 ,使充填砂体固结。聚酯纤维可防止覆膜砂在固结前反吐。在室内模拟条件下确定酚醛树脂熔点为 96℃ ,以乌洛托品与表面活性剂等辅剂的复配物为固化剂 ,固化剂溶液浓度为 2 5 0～ 30 0 g/L。在使用清水携砂、配液条件下 ,在 6 5℃固化 3天后固结砂抗折、抗压强度达 2 .5和4 .3MPa ;随固化温度升高 ,固结砂强度升高 ,在 70℃固化后强度接近稳定值 ,在 12 0℃固化后强度急剧升高。改用海水时 ,在 70℃固化后抗折、抗压强度分别达 2 .4和 4 .8MPa ;在 6 0℃下不加固化剂时至少在 5天内不固化 ,加入固化剂后 3天强度达到 2 .4和 4 .9MPa。LH Ⅱ固结砂耐清水、海水、原油、盐溶液 (压井液 )、10 %盐酸、季铵盐溶液浸泡 ,但不耐碱 (5 %NaOH溶液 )。表 3参 6。

A sand control agent,LH-Ⅱ,is prepared for use in production wells with multiple paylayers in loosely consolidated sandstone reservoirs in their middle-late stages of development.The quartz sand is coated with a phenolic resin in alcohol solution with a coupling agent added and then admixtured with polyester fiber of D=1.2 mm and L=8.0 mm in mass ratio 100∶3 to give fiber admixtured coated sand LH-Ⅱ.The sand LH-Ⅱ is carried by oilfield produced or sea water to fill in the sand loss zones and,after all the downhole jobs having been completed,the curing agent in solution is injected and consolidation of the sand packs takes place.The polyester fiber admixtured prevents the sand particles from flowing out of the well.Under laboratory simulation conditions a phenolic resin of melting point=96℃ and a compounded curing agent (CCA) of urotropine with surfactant and other auxilaries are selected and the CCA is used in 25-30% aqueous solution.When fresh water is taken as sand carrying fluid and for CCA solution preparing,the flexural and compression strength of the consolidated LH-Ⅱ sand packs cured at 65℃ in 3 days reaches 2.5 and 4.3 MPa and the strength increases with increasing curing temperature:approaches to stable values when cured at 70℃ and reaches very high values - at 120℃.When sea water is taken instead,the flexural and compression strength of the consolidated LH-Ⅱ sand packs cured at 70℃ is of 2.4 and 4.8 MPa;the LH-Ⅱ sand packs without curing agent added do not consolidate at 60℃ in 5 days and that with curing agent added have flexural and compression strength of 2.4 and 4.9 MPa after being cured at 60℃ in 3 days.The consolidated LH-Ⅱ sand packs keep stable after being immersed in fresh and sea water, crude oil, a salt solution (well load fluid),10% hydrochloric acid and a quarternary ammonium (clay stabilizer) solution but desintegrate in alkaline (5%NaOH)solution.