Coretrax 开发了 ReLine MNS 技术，该技术提供了无需铣鞋的单程解决方案。该技术包覆和密封了各种井眼完整性问题，内径 (ID) 损失最小，同时提供高爆破和塌陷等级（图 1）。

套管孔系统设计用于部署在接头管道上，可以覆盖从 30 英尺到 7,000 英尺的长或短井段。它可以配置为在井眼中的各种内径限制（例如接头或压裂套管）上扩展和密封。

该技术允许对成熟井筒进行重新完井，从而能够采用现代压裂设计进行重复压裂，正如新墨西哥州东南部老式压裂完井的老骨泉地层井所成功证明的那样。

隔离现有穿孔

Bone Spring 地层位于特拉华山脉正下方、Wolfcamp 地层上方。它由厚度达 4,000 英尺的互层（沉积在现有层之间）硅质碎屑岩、碳酸盐岩和页岩组成，分为四个层段，每个层段的渗透率都非常低。

随着水力压裂和水平钻井的引入，碳氢化合物产量大幅增加。Bone Spring 的生产井数量从 2005 年 1 月的 436 口增加到 2019 年中期的 4,338 口，平均月产量达到 0.6 Mbbl 原油和 1.7 Bcf/d 天然气。

虽然美国能源信息管理局 (EIA) 预计 Bone Spring 产量将推动二叠纪盆地的增长，但老式井的产量低于相同面积的新井的产量。因此，使用原始生产趋势预测的欧元值并不经济。

此外，井筒周围的损耗水平被认为很小。由于井口额定压力为 10,000 psi，因此不需要井口隔离工具来测试套管至 6,200 psi，这是压裂处理期间爆破额定值和预期压力的 80%。由于产量较低，因此推测井眼周围的枯竭程度较低。每英尺支撑剂体积更高的额外压裂阶段将增加增产储层体积，并有助于提高采收率。

单程工具

计划对该井进行的跟部压裂遇到了操作问题，由于该井通过了重复压裂选择标准，最终决定进行全侧向重复压裂。与其他可膨胀系统不同，ReLine MNS 送入工具配置可以在液压膨胀过程中与内管柱膨胀机构分离。这使得衬里能够在多种负载条件下膨胀。重要的是，在锚定顶部密封件并与内绳一起退出衬里之前，可以将其保留在中间位置。这种中性负载条件对于严重压裂井下环境中的可靠性至关重要。

在准备过程中，人工举升设备被从井中拉出，并在膨胀衬管顶部的计划深度处设置了可回收桥塞，以测试原始 5 陆英寸套管的完整性。需要多次清洗起下井来清洁侧井筒部分。为了确保衬管能够运行到预定深度并展开，进行了通流。然后将衬管在内管柱上入孔，没有出现任何问题（图 2）。

膨胀锥通过液压方式启动，以膨胀底部锚定密封件，将衬管固定到原始套管上。然后使用超拉力对剩余的衬里进行机械扩张。在最后一个接头处，重量减轻，使膨胀的衬管处于中立状态，从而释放了衬管接头中的所有张力。然后，顶部锚定密封件通过液压膨胀，将衬管顶部锚定到原始套管上。

更高的可靠性和更高的产量

使用可膨胀衬管技术进行机械隔离是一种比固井套管重新衬砌先前生产层段的重复压裂井更可靠、更有效的方法。操作员表示，由于能够使膨胀的衬管处于中立状态，同时利用超拉保持膨胀衬管的速度，因此这将是未来全侧向重复压裂的首选系统。

重复压裂释放未采收的储层

据估计，每口井的钻探和完井成本可达 500 万至 1000 万美元。在当今成本受限的环境下，完全横向重复压裂能够以比新钻探井更低的成本释放未采储量。

虽然操作员可以使用原始地面设备和原始井筒，但获得第二口樱桃的相关风险取决于胚胎技术的开发和可用性。可扩展技术的使用是十年前不可能出现的新创新的理想例子。与任何作业一样，与未知且更具成本效益的作业相比，众所周知但成本较高的作业所面临的风险是支持有效、高效和可持续钻井和完井发展的日常难题。

Coretrax has developed ReLine MNS technol­ogy, which provides a single-trip solution with no shoe milling. The technology clads and seals various wellbore integrity concerns with minimal loss of inner diameter (ID), while providing high burst and collapse ratings (Figure 1).

The cased-hole system is designed for deployment on jointed pipe and can cover long or short intervals from 30 ft to 7,000 ft. It can be configured to expand and seal across various ID restrictions in the wellbore such as nipples or frac sleeves.

This technology allows mature wellbores to be recompleted enabling refracturing with modern frac designs, as successfully demonstrated in an older Bone Spring Formation well with vintage frac completions in southeast New Mexico.

Isolating existing perforations

The Bone Spring Formation lies directly under the Delaware Mountain Group and over the Wolfcamp Formation. It consists of interbedded (settled between existing layers) siliciclastic, carbonate and shale rocks up to 4,000 ft thick and is divided into four intervals—each of which has very low permeability.

With the introduction of hydraulic fracturing and horizontal drilling, hydrocarbon production has increased considerably. The number of producing wells in the Bone Spring grew from 436 in January 2005 to 4,338 wells in mid-2019, when average monthly production reached 0.6 MMbbl of crude oil and 1.7 Bcf/d of natural gas.

While the U.S. Energy Information Administration (EIA) expects Bone Spring production to drive growth in the Permian Basin, the produced volumes in vintage wells were lower than new wells in the same acreage. Therefore, the forecasted EUR values, using the original production trends, were not economic.

Additionally, the level of depletion around the well­bore was presumed to be small. As the wellhead was rated to 10,000 psi, a wellhead isolation tool was not needed to test the casing to 6,200 psi, which was 80% of the burst rating and the expected pressure during the frac treatment. Since the produced volumes were low, the level of depletion around the wellbore was presumed to be low. Additional frac stages with higher proppant volumes per foot would increase the stimulated reservoir volume and would contribute to higher recovery.

Single-trip tool

A heel frac planned for this well had run into oper­ational issues, and eventually it was decided to per­form a full-lateral refrac since the well passed the refrac selection criteria. Unlike other expandable systems, the ReLine MNS running tool configura­tion can be decoupled from the inner string expan­sion mechanism during the hydraulic expansion process. This allows the liner to be expanded in multiple load conditions. Importantly, it can be left at a neutral position before anchoring the top seal and exiting the liners with the inner string. This neutral load condition is critical for reliability in severe fracturing downhole environments.

In preparation, artificial lift equipment was pulled from the well and a retrievable bridge plug was set at the planned depth on top of the expanded liner to test the integrity of the original 5½-inch casing. Multiple cleanout trips were needed to clean the lateral wellbore section. To ensure the liner could be run to the intended depth and expanded, a drift was performed. The liner was then run in-hole on an inner string without any issues (Figure 2).

The expansion cone was activated hydraulically to expand the bottom anchor seals, securing the liner to the original casing. The remaining liner was then expanded mechanically using overpull. At the last joint, weight was slacked off to put the expanded liner into neutral, relieving all the tension in the liner joints. The top anchor seals were then expanded hydraulically to anchor the top of the liner to the original casing.

Greater reliability and increased production

Mechanical isolation using expandable liner tech­nology is a more reliable and effective method for refracturing wells than cementing casing to re-line the previous producing interval. With the ability to leave the expanded liner in neutral while maintaining the speed of expanding the liner using overpull, the operator stated this would be the system of choice for future full-lateral refracturing.

Refracturing unlocks unrecovered reservoirs

It is estimated that drilling and completion of a new well can range between $5 million and $10 million per well to perform. In today’s cost constrained cli­mate, full-lateral refracturing unlocks unrecovered reserves at a lower cost than newly drilled wells.

While the operator will have access to original surface equipment, and the original wellbore, the risk associated with getting that second bite of the cherry is dependent on embryonic technology development and availability. The use of expandable technology is the ideal example of new innovation that would not have been available a decade ago. Like any operation, the risk of doing what is well known but expensive compared to what is unknown and more cost-effective is the daily conundrum to support the evolution of effective, productive and sustainable drilling and completion.