防膨抑砂剂NTW-1及其深部稳砂技术

Clay Stabilizer/Sanding Inhibitor NTW-1 and Indepth Sand Control Using This Agent

使丙烯酰胺、阳离子单体在水溶液中引发聚合,聚合产物再与偶联剂反应,得到主链为碳链、季铵盐基团在支链末端的阳离子聚合物,代号NTW-1.与国内外多种类似功能化学剂对比,NTW-1与国产防膨剂FSJ-03使蒙脱石晶面间距降至最小的溶液浓度小(20 g/L),处理后储层岩心对蒸馏水的渗透率下降幅度小;NTW-1的防膨率最高(离心法为93%,膨胀仪法为90%),抑砂性能最好(冲砂流出液浊度、含砂量最小);因此NTW-1被选作深部稳砂用的防膨抑砂剂.固砂剂GSJ-8的60℃固结砂抗压强度高(5.8 MPa)、渗透率保持率高(87.7%),与NTW-1配伍性良好.在填砂管中依次注入20 g/L的NTW-1溶液、50～60 g/L的GSJ-8溶液、后置液,在60℃放置48小时后,固结砂抗压强度5.0～5.7 MPa,渗透率保持率90%～96%.由NTW-1和GSJ-8组成的体系可防止深部充填砂的运移,可用于出砂不太严重的疏松砂岩油藏的深部稳砂防砂.在现场施工中,用泵车交替注入NTW-1和GSJ-8溶液,其用量由油井出砂情况计算.截止2004年底,在300余口油井进行了深部稳砂作业,施工有效率92.9%,共增产原油45万吨.表6参5.

A cationic polymer, NTW-I, with C---C main chain and terminal quartemary ammonium salt functionalities on branches is prepared by initiated polymerization of acrylamide and cationic monomer in aqueous solution and reaction of the copolymer obtained with a coupling agent. In a series of laboratory comparative experiments, the lowest solution concentration, 20 g/L, needed for montmorillonite to reach its smallest crystal plane spacing and the smallest decrement in permeability of reservoir cores to distilled waterare observed when working with NTW-1 and FSJ-03, a home made clay stabilizer; the highest antiswelling rate, 93% （centrifugal method） or 90% （expansion measurement） and the highest sanding inhibition capacity （the lowest turbidity of and the lowest sand content in flown washing water） are observed when working with NTW-1. Therefore NTW-1 is chosen as clay stabilizer/ sanding inhibitor for indepth sand control operations （IDSCOs）. A sand consolidation agent, GSJ-8, is chosen for IDSCOs, too, as it gives consolidated sand packs of high compression strength, 5.8 MPa, and high permeability retention, 87.7%, and is compatible well with NTW-1. The consolidated sand packs obtained by treating with 30 g/L NTW-1 sotulion, 50-60 g/L GSJ-8 solution, and postpad in turn and by maintaining at 60℃ over 48 hrs possess compression strength 5.0-5.7 MPa and retain 90-96 % original permeability. The NTWol/GSJ-8 system can prevent transfer of filling sands in deep reservoirs and be used for IDSCOs in loosely consolidated sandstone reservoirs with minor sand problems. In field operations the NTW-1 and GSJ-8 solutions are injected alternatively into the production wells with unsevere sand troubles by a pump truck in amount depending on sand produetion rate. Up to the end of 2004,IDSCOs have been performed in more than 300 wells with 92.9% effeetiveness and 450 thousands tones of crude oil were produced additionally.