斯伦贝谢近日推出了压裂系统—Falcon多级压裂系统，并配有一系列高效井下工具。
编译 | 惊蛰 影子
Falcon多级增产系统能够隔离不同产层，可以连续进行不同产层的基质酸化增产或水力压裂增产作业，该系统适用于包括水平井、斜井和垂直井在内的多种井况。在具体应用中，Falcon系统利用可膨胀或液压坐封封隔器，实现不同产层间的隔离，之后，通过地面投掷不同直径的密封球，即可实现产层的连续增产作业。
通路循环与液压控制压裂密封球
Falcon配置有通路循环阀，在工具下入过程中管串也具有液体循环功能。当尾管抵达预定深度，从地面投入密封球，将其泵至球座，既可永久的关闭循环阀门。随后升压，完成产层间封隔器坐封，激活水力压裂阀，实现产层与井筒之间的连同。
液压坐封与膨胀封隔器
Falcon系统的封隔器原件经过特殊工程设计，采用了复杂的聚合物技术，适用于高压作业，可同时满足增产与生产的要求。液压坐封封隔器通过压力激活主动锁定功能，压力的增加激活封隔器膨胀密封元件，与底层接触，实现密封。
ResPack膨胀密封封隔器与管串连接，其密封胶体与中心管相连，在井液（水或油）接触后自动膨胀，实现密封。该封隔器具备延迟膨胀机制，防止其过早膨胀，无需额外的外部涂层。值得强调的是ResPack封隔器没有任何可移动部件，安全性很高。
投球激活压裂阀
随着产层深度连续变化，地面投入的密封球直径逐渐增加，落入到不同的球座中，依次打开不同产层的压裂阀，与目标区域建立连通。压裂阀为球形设计，防止在压裂过程中发生卡球及下部产层的生产漏失。压裂球采用ELEMENTAL可降解技术，在井底条件下可完全自主降解，消除了压裂作业后回流或磨球的需要。
尾管顶部封隔器
Falcon系统具有一系列不同规格的尾管挂、尾管顶部封隔器，可以满足任何状况下客户的增产作业要求。目前，该系统的尾管顶部封隔器已经通过了ISO 14310 V3标准，尾管挂可通过机械右旋释放工具（RRT）、液压投入工具（CRT）等安装。此外，这两种工具具有不同长度的密封孔系统，可满足其与不同规格尾管的回接作业。
尾管挂/封隔器
A.PV-3级重量坐封尾管顶部封隔器
用于悬挂HPS液压尾管：
1.满足ISO 14310 V3标准；
2.可与压裂管串进行TBR回接操作；
3.内置卡瓦设计，防止尾管滑动；
4.液体流通面积大，有助于井筒清洁，减少循环洗井时间；
5.内置适配器，下入管串可以承受高扭矩；
6.最大直径可达8.445in。
B.液压旋转尾管挂
悬挂大质量尾管时可进行旋转操作：
1.舌槽式滑动插入设计，可最大限度地减少下入干扰和应力，消除锥形塌陷风险；
2.减少对套管冲击的压力；
3.提高水泥和井筒完整性，作业更安全。
Falcon系统封隔器
C.液压坐封裸眼封隔器，隔离相邻的待增产产层
1.坐封压力2400 psi；
2.全方位的作业保护；
3.封隔器两端都有防拖拉元件和轴承，防止挤压损伤；
4.内置密封圈，在封隔器坐封后提供永久的坐封力，并且可以多次循环使用；
5.特殊设计，可同时进行多个封隔器的坐封。
D. ResPack膨胀封隔器
隔离待激活产层：
1.使用温度范围广（37-185°C），可承受压差达103MPa，是目前业内最高压；
2.内置膨胀延迟机制，降低提前膨胀风险；
3.膨胀体直接与中心管连接，无移动部件，耐用，具有自我修复功能；
4.适用于所有流体类型。
Falcon阀门
E．投球激活压裂阀门
可建立待压裂产层与井筒之间的连接：
1.抗旋转机制，投球与球座的磨铣更容易；
2.流出口面积大，最大化流通面积；
3.在球座磨铣前后可重复开启、关闭；
4.多球座设置，可增加流量；
5.磨铣直径3.75 in。
压裂投球与球座
球座的球形设计有助于密封球的回收，同时防止压裂作业中发生卡球问题，投球回收压力仅为500psi，为业内最低。
1.镁合金材质，重量小，耐用，防抗击损伤，磨铣容易；
2.基于工程数据计算，直径增加采用非线性增加模式，便于产层增产作业；
3.密封球具有ELEMENTAL可降解技术选项，可避免后期的压裂球移除操作，节约时间和成本；
4.球座模块化设计，易于磨铣移除。
F.液压激活压裂阀
在井底第一个产层增产作业完成后，关闭流通循环阀，即可建立底层与井筒的连通，
1.每个操作系统仅有一个阀门，安装于通路回流循环阀上方
2.坐封压力约为5,500 psi
3.液体流出口面积大，允许高流速液体通过
G.通路循环阀
在工具下入过程中管串具有液体循环功能，将其关闭后可建立产层间的隔离：
1.在工具到达指定位置、投球后，激活压力1,500 psi；
2.球座尺寸可调，可满足多级压裂作业的要求，无需更换阀门；
3.在压裂初始阶段，无需对尾管施加作用力。
技术应用
水平井，斜井以及垂直井的多级压裂、隔离基质酸化处理、完整性缺失井的增产作业、砂岩/碳酸盐岩/页岩的增产作业。
技术优点
1.一次下钻完成安装，减少作业时间，降低作业风险；
2.模块化设计，具有多种配置设计，根据现场变化可及时调整，提高作业效率；
3.无需电缆及连续油管操作，降低作业成本。
技术特点
1.可降解压裂球技术，无需压裂后的回流及磨球作业；
2.球座几何形状优化，在井筒清洗中低压即可回收密封球；
3.球座可轻松磨铣清楚，井筒尺寸不受影响，使产量最大化；
4.压裂阀可重复关闭，产层压裂后可实现暂时隔离；
5.膨胀封隔器采用膨胀滞后机制，防止其提前膨胀。
Falcon* multistage stimulation system isolates zones and enables them to be treated continuously during matrix acidizing stimulation or hydraulic fracturing treatments in horizontal, deviated, and vertical wells. The system uses swellable or hydraulically set packers between zones for isolation. Balls with gradually increasing diameters are dropped from surface to enable treatment of successive zones.
Flow-through circulating and hydraulically actuated frac valves
The flow-through circulating valve enables circulation while the system is being run in the hole. When the liner reaches the desired position, a ball is dropped from surface and pumped down until it lands on the ball seat, permanently closing the circulation valve. Pressure can then build up to set the hydraulic packers and actuate the hydraulic frac valve, enabling communication with the first fracture zone.
Hydraulically set and swellable packers
Falcon system packer elements are engineered from a complex polymer suited for high-pressure applications to achieve sealing during stimulation as well as production. Hydraulically set packers use pressure to activate a positive-lock mechanism that expands the packer element, sealing against the formation.
ResPack* swellable bonded-to-pipe packers are designed to swell on contact with fluid—water or oil. The elastomer is bonded directly onto the basepipe. An integral delay mechanism engineered into the polymer minimizes the risk of premature swelling and setting without the need for any additional exterior coating. The packer has no moving parts.
Ball-actuated frac valve
Progressively larger balls are dropped from surface to seat in and shift open the ball-actuated frac valves, establishing communication with the zones of interest. The frac valves use spherical ball-seat geometry to prevent stuck balls during fracturing and the consequent loss of production from the zones below. Use of ELEMENTAL degradable technology frac balls eliminates the need to flow back or mill the balls after fracturing because they degrade predictably and fully at bottomhole conditions.
Liner-top packer
With a full range of liner hanger assemblies and liner-top packers within the Falcon system portfolio, a fit-for-purpose solution can be provided for the deployment of stimulation systems and securing of the system in the well. The liner-top packer elements are ISO 14310 V3 qualified. The liner hanger system can be deployed via a mechanical right-hand-release running tool (RRT), hydraulic collet running tool (CRT), or latchdown tool. Optional sealing bores of various lengths are available for liner tieback in latched or unlatched seal assembly applications.
Liner hanger and packer
A. PV-3 weight-set liner top packer
Holds HPS hydraulic pocket-slip liner hanger
1.ISO 14310 V3 qualification?
2.TBR tieback receptacle for tying in fracturing string
3.Hold-down slips to prevent upward movement of liner
4.Large fluid bypass area that aids inhole cleaning and reduces circulation time
5.Integral mandrel and setting adapter to permit transmission of high torque from running string to liner
6.Maximum OD of 8.445 in [214.5 mm]
B. HPS hydraulic rotating pocket-slip liner hanger
Hangs heavy liners while rotating
1.Tongue-and-groove pocket slip design that minimizes running interference and stress and eliminates cone collapse
2.Reduced burst pressure on casing
3.Enhanced cement integrity and well stability and safety
Falcon packer options
C.Hydraulic-set openhole packer Isolates adjacent stages being stimulated
1.Setting pressure of 2,400 psi [16.54 MPa]
2.Full gauge protection
3.Antiswab elements and barrier rings on both sides of element that prevent extrusion
4.Internal lock ring that permanently retains setting force in element after packer is set, permitting multiple pressure reversals
5.Design that allows multiple packers to be set simultaneously
D. ResPack* swellable bonded-to-pipe packer
Isolates adjacent stages being stimulated
1.Available for a wide temperature range, from 100 to 365 degF [37 to 185 degC], and with a differential pressure rating of up to 15,000 psi [103 MPa], the highest psi/ft rating in the industry
2.Built-in swelling delay mechanism that reduces risk of premature setting
3.Elastomer bonded directly onto basepipe; no moving parts; durable, self-healing construction
4.Suitable for all fluid types
Falcon valves
E. Ball-actuated frac valve
Allows communication to be established with each zone to be fractured
1.Antirotational device that enables easy milling of balls and seats
2.Large exit ports to maximize flow area
3.Reclosable feature with ability to close the sleeve before and after milling the seats
4.Multiple-ball seats for increased flow rate
5.Millout ID of 3.75 in [95.25 mm]
Frac ball and ball seat
The spherical ball seat geometry promotes ball flowback and prevents stuck balls during fracturing. All balls flow off seats at <500 psi [<3.447 MPa] back pressure, the lowest in the industry.
1.Magnesium balls that are light, strong, extrusion resistant, and easy to mill
2.Balls with nonlinear increments based on engineering calculation of load forces for every stage
3.Optional ELEMENTAL degradable technology frac balls, which eliminate the need for interventions to remove frac balls, saving time and costs
4.Segmented seats for easy millout into small pieces
F. Hydraulically actuated frac valve
Allows communication to be established with first fracture zone at toe after close of flowthrough circulating valve
1.Only one valve per system, situated above flow-through circulating valve
2.Setting pressure of ~5,500 psi [~37.92 MPa]
3.Large exit ports that increase flow area, allowing high flow rates
G. Flow-through circulating valve
Allows fluids to circulate while system is run inhole and then closes to isolate internal casing from annulus
1.Activation pressure of 1,500 psi [10.34 MPa] by ball dropped from surface after system reaches TD
2.Ball seat sizes that are easily interchanged at wellsite to accommodate change in number of stages being stimulated without new valves needed
3.Elimination of piston force on liner assembly during initial fracture
APPLICATIONS
Horizontal, deviated, and vertical wells for
–multistage fracturing
–isolated matrix acidizing treatments
–stimulation when a well has casing integrity issues
–stimulation of sandstone, carbonate, and shale plays
BENEFITS
1.Single-trip installation that reduces rig time and operational risks
2.Improved efficiencies due to modular design that accommodates multiple configurations and last-minute modifications
3.Reduced costs with elimination of wireline and coiled tubing operations
FEATURES
1.ELEMENTAL* degradable technology frac balls, which eliminate the need to flow back or mill frac balls after fracturing operations
2.Seat geometry that promotes ball flowback at lower pressures during fracture cleanup
3.Drillable seats for fullbore access and increased production output
4.Reclosable ball-actuated frac valves for zonal shutoff after fracturing
5.Delayed swelling of swell packers for reduced risk of premature setting.