套管/固井/分区隔离

ZoneStop——区域隔离的创新方法

TAQA 扩展了其高端技术组合,开发了高性能射孔堵塞专利产品。

由...赞助 TAQA_Logo_Eng.jpg

在井的整个生命周期中,可能有必要隔离现有的射孔,以便重新完成井眼的替代部分或防止从给定区域或间隔产生不需要的流体,例如水。

传统方法可能涉及设置塞子、跨射孔或进行化学或水泥挤压,所有这些都可能复杂且成本高昂,并且通常会导致进入井眼的通道受到限制。

为了应对这些挑战,TAQA 开发了 ZoneStop,这是一种经济高效、低复杂性的专利产品,可隔离现有射孔和/或地层层段,从而实现目标区域的关闭和永久隔离。 ZoneStop可以有效密封并防止流入和流出目标区间。

如图1所示,ZoneStop是一种在表面形成浆料的一定尺寸的可溶胀弹性体颗粒混合物,然后从表面泵入目标区域并允许原位溶胀以提供有效的密封。

可溶胀颗粒在地面分批混合,并使用标准固井或钻机设备泵入井下。颗粒材料和载液的设计和体积基于井条件和设计以及需要隔离的区域的特性。可膨胀弹性体颗粒基于专有配方,专门设计用于在井下条件下膨胀。溶胀机制由超吸收性聚合物和渗透成分的组合驱动,以优化溶胀过程的速度和强度,同时确保耐化学性和堵塞持久性。

区域停止.jpg
图 1——oneStop 属性和性能。

该技术已被部署在不同的应用中,例如非常规油藏重新完井和重复压裂之前的强化水泥浇注和射孔隔离。

对于堵塞和废弃的应用,ZoneStop 已在二叠纪盆地作为水泥前体应用,以帮助解决生产套管和中间套管之间的气体运移问题。 ZoneStop 在较长一段时间内控制了损失并实现了有效的水泥浇注。借助 ZoneStop,该井成功封堵并满足了​​监管要求。在该处理之后,没有观察到生产套管与中间套管环空或中间套管与表层套管之间的环空上出现压力积聚。

该技术已在多次现场试验中得到应用,可有效隔离射孔层段。

在一项应用中,ZoneStop 用于选择性地隔离射孔,以防止损失并实现另一区域的砾石充填。这表明可膨胀材料可用于替代水泥来隔离麻烦的射孔,同时保持井内的全通径通道。

在另一个应用中,ZoneStop 用于隔离天然气发生炉中的含水区域。通过将可膨胀颗粒泵入孔眼来选择性地隔离含水层。通过压力测试验证穿孔的隔离。处理后,生产区恢复生产,并保持所有层段的全井眼通行。

为了提高可能因大孔洞、裂缝或水泥隔离不良而导致的较大空隙区域的堵塞性能,已经开发了该技术的扩展。

开发了一种新型粘合剂,通过固结可膨胀颗粒来提高堵塞效率。初始测试是使用专门设计的复制裂缝的装置进行的,其中每次测试的裂缝孔径都可以变化。制备颗粒和粘合剂浆料,然后施加压力以迫使该浆料通过裂缝孔。如果形成堵塞,则将压差增加到最大 500 psi 以评估堵塞完整性。这些第三方插槽测试表明,添加温度激活粘合剂后,堵塞潜力显着增强。

下一代 ZoneStop 可以堵塞高达 12.7 毫米的缝隙间隙,而单独颗粒浆料的缝隙间隙为 3.5 毫米。在测试过程中,当施加在塞子上时,塞子能够始终承受 500 psi 的压差。

ZoneStop 的这一扩展使得在更恶劣的条件下(例如裂缝地层、孔洞、大套管泄漏和重复压裂)实现层间封隔成为可能。这种新方法还有助于减少创建有效且永久的塞子所需的材料总量。

本着这种精神,TAQA 还在评估该技术在防止钻井液循环漏失方面的应用,这是钻井和固井作业面临的主要挑战之一,其中材料足够小,可以穿过钻头,然后膨胀到更多其规模的两倍以上将产生重大的积极影响。

塔卡标志

原文链接/jpt
Casing/cementing/zonal isolation

ZoneStop—An Innovative Approach to Zonal Isolation

Expanding its portfolio of high-tier technologies, TAQA develops a high-performance perforation-plugging patented product.

Sponsored By TAQA_Logo_Eng.jpg

Throughout the life of a well, it may be necessary to isolate existing perforations for the purpose of recompleting an alternative section of the wellbore or to prevent the production of unwanted fluids such as water from a given zone or interval.

Traditional methods may involve setting a plug, straddling the perforations, or performing a chemical or cement squeeze, all of which can be complex and costly and typically result in restricted access to the wellbore.

To address these challenges, TAQA developed ZoneStop, a cost-effective, low-complexity, patented product that isolates existing perforations and/or formation intervals enabling shutoff of the target zone and permanent isolation. ZoneStop can effectively seal and prevent flow into and out of the target interval.

As shown in Fig. 1, ZoneStop is a sized, swellable elastomer particulate blend slurried at surface, then pumped from the surface into the target zone and allowed to swell in situ to provide an effective seal.

The swellable particulates are batch-mixed at surface and pumped downhole using standard cementing or rig equipment. The design and volume of the particulate material and carrier fluid are based on the well conditions and design, and on the properties of the zone requiring isolation. The swellable elastomer particles are based on a proprietary recipe that is purposely designed to swell under downhole conditions. The swelling mechanism is driven by a combination of superabsorbent polymers and osmotic components to optimize the speed and strength of the swelling process while ensuring chemical resistance and plug permanence.

zonestop.jpg
Fig. 1—ZoneStop properties and performance.

This technology has been deployed in different applications such as enhanced cement placement and perforation isolation prior to recompletion and refracturing of unconventional reservoirs.

For applications in plug and abandonment, ZoneStop has been applied in the Permian Basin as precursor to cement to help cure gas-migration issues between the production and intermediate casing. ZoneStop controlled losses for an extended period of time and enabled effective cement placement. With ZoneStop, the well was successfully plugged and regulatory requirements were satisfied. No pressure buildup on annuli between the production casing and intermediate casing annulus or intermediate casing and surface casing was observed after this treatment.

The technology has been applied in multiple field trials to effectively isolate perforated intervals.

In one application, ZoneStop was applied to selectively isolate perforations to prevent losses and enable gravel packing of another zone. This demonstrated that the swellable material could be used to replace the cement in isolating troublesome perforations while maintaining fullbore access in the well.

In another application, ZoneStop was applied to isolate a water-bearing zone in a gas producer. The water-bearing zone was selectively isolated by pumping the swellable particulates into the perforations. Isolation of the perforations was verified by pressure test. The producing zone was returned to production after the treatment, and fullbore access to all intervals was maintained.

To enhance plugging performance for zones with larger void spaces that may result from large vugs, fractures, or from poor cement isolation, an extension of the technology has been developed.

A novel binding agent was developed to improve the plugging efficacy by consolidating the swellable particulates. Initial testing was conducted using a specially designed apparatus replicating a fracture where the fracture aperture could be varied for each test. The particle and binder slurries were prepared and then pressure was applied to force this slurry through the fracture aperture. If a plug was formed, then the differential pressure was increased to a maximum of 500 psi to evaluate the plug integrity. These third-party slot tests demonstrated a significant enhancement in plugging potential with the addition of the temperature-activated binding agent.

The next generation of ZoneStop can plug slot gaps up to 12.7 mm compared with 3.5 mm for the particulate slurry alone. The plug was capable of consistently withstanding 500-psi pressure differential during testing when applied against the plug.

This extension of ZoneStop opens the possibility of zonal isolation under more severe conditions such as fractured formations, vugs, large casing leaks, and for refracturing. This new approach can also help to reduce the overall quantity of material required to create an effective and permanent plug.

In this spirit, TAQA is also evaluating the application of this technology to prevent lost circulation of drilling fluids, one of the main challenges facing drilling and cementing operations, where having material that is small enough to fit through a drill bit and then swell to more than twice its size will create a significant positive impact.

TAQA logo