一次多层砾石充填防砂工艺针对套管内同时射开多层的油气井，且每层均需要充填防砂完井。
该工艺可一次下入多层防砂工具及服务工具，逐层坐封、充填，层与层之间由隔离密封和隔离封隔器隔离保证充填液不会串层。可实现一次管柱下入完成多层不等距产层的砾石充填 防砂作业，大大缩短完井时间。
● 拥有9-5/8”及7-5/8”、7”一次多层砾石充填系统；
● 可实现单井多层一趟管柱完成封隔器坐封和各层分别充填作业，提高作业效率；
● 一趟管柱下入多层防砂工具及服务工具；
● 定位工具定位充填位置，防止管柱充填时移位；
● 任何一层充填时与其他层隔离，防止完井液漏失；
● 每一层充填后可进行验充填，若充填效果不好可再次充填。
井筒工具管柱结构为：
顶部封隔器+pack off密封舱+密封筒+上延伸筒+充填滑套+下延伸筒+定位接箍+筛、盲管+隔离封隔器+上延伸筒+充填滑套+下延伸筒+定位接箍+筛、盲管(根据层数重复隔离封 隔器至筛盲管部分)+snap latch插入密封+沉砂封隔器等。
各工具之间连接除了采用LTC套管扣外，还普遍采用 ACME螺纹连接，连接强度高；工具之间端面定位普遍通过 斜面定位，具有防止工具旋转和辅助密封作用。
服务工具管柱结构为：
坐封工具+pack off+4”&2 7/84”冲管+中部密封+充填 工具GP Tool+MARS阀+负荷显示器+滑套单关工具+滑套开 关工具+底部密封等。
各工具之间连接大多采用平扣+O圈形式，减小壁厚，增 大内径外，连接强度高；工具之间端面定位普遍通过斜面定位，具有防止工具旋转和辅助密封作用。
ONE-TRIP MULTI-ZONE GRAVEL PACK SYSTEM (CMP)
One-trip multi-zone gravel pack system is used for the oil&gas wells with multiple perforated zones with each zone requiring gravel pack.
The process can be one-time trip in multi-zone service tools, zone- by-zone setting, pack, sealing and isolating to prevent leaking, realizing one-trip multi-zone unequal distance net pay gravel pack operations, greatly reducing well completion time.
◎ It has 9-5 / 8 "and 7-5 / 8", 7 "primary multi-layer gravel packing system;
◎ One-trip string, realizing packer setting and each_ x005fzone separated pack for single-well multi-zones, high operation efficiency;
◎ One-trip string for multiple sand-control service;
◎ Locating tool for the pack ,preventing string moving during pack;
◎ Isolation between layers when pack, preventing completion fluid leaking;
◎ Examination after every-layer pack, repack if necessary.
String tool descriptions
Wellbore tool string structure:
top packer + pack off Assembly + sealing tub + upper extension +pack sliding sleeve + lower extension + collar locator + sand screen/blank pipe + isolation packer + upper extension + pack sliding sleeve + lower extension + collar locator+ sand screen/blank pipe +snap latch + sump packer The string uses ACME thread connecting with higher joint strength besides using LTC casing thread, and the tool surface location uses contour localization, having the function to prevent tool rotating and to assist sealing.
Service tool string structure:
Setting tool + pack off + 4"&2-7/8"wash pipe + middle seal + GP Tool + MARS valve + load indicator + one way tool + two way tool + lower seal. Mostly using tougue&groove system+ O-ring to connect tools, reducing wall thickness, increasing the insider/outsider diameter, higher joint strength; commonly using contour localization for the tool surface location, functioning in preventing tool rotating and assisting sealing.