高效技術(shù)到來 棄置封堵不再添堵-石油圈

HydraWell推出的棄置封堵技術(shù)一次下鉆即可完成作業(yè)，作業(yè)效果顯著改善。

編譯 | TOM 驚蟄

自2017年5月以來，HydraWell一直在執(zhí)行Valhall油田老鉆井平臺(tái)（DP）10口已關(guān)停油井的棄置封堵作業(yè)。近日，通過在Valhall油田使用PWC（射孔/清洗/注水泥）封堵棄井（P＆A）技術(shù)，HydraWell公司成功幫助Aker BP提前完成了封堵計(jì)劃。

與2014年至2016年DP平臺(tái)上第一階段的封堵棄井作業(yè)相比，Aker BP在最新階段將每口井的平均作業(yè)時(shí)間減少了50％，盡管在作業(yè)結(jié)束時(shí)井筒復(fù)雜性有所增加。在DP平臺(tái)上執(zhí)行井筒封堵是Valhall油田邁向現(xiàn)代化的關(guān)鍵部分。從1982年開始采油的三個(gè)老平臺(tái)QP、DP與PCP將被拆除，在移除DP平臺(tái)之前，需要將剩余四口井永久封堵。

Aker BP公司封堵棄井部門工程經(jīng)理Martin Straume說：“通過改進(jìn)一些關(guān)鍵元素，我們顯著縮短了封堵棄井作業(yè)的時(shí)間。HydraWell公司的HydraHemera PWC技術(shù)就是這些主要元素之一。除此之外，我們還進(jìn)行了計(jì)算機(jī)模擬，以確定在固井開始之前，需要多長(zhǎng)時(shí)間清洗套管內(nèi)壁。這加深了我們的認(rèn)知，意味著我們可以比以前更快的完成作業(yè)。”

Straume補(bǔ)充道：“此外，我們與HydraWell一起，已經(jīng)開始在適用的油井中下入單趟作業(yè)系統(tǒng)。這意味著我們將射孔槍下入井中，而不是在我們開始清洗之前將其起出。這有助大幅縮短作業(yè)時(shí)間。”HydraWell公司的HydraHemera PWC系統(tǒng)在清洗套管前，對(duì)油井進(jìn)行射孔，然后注入水泥塞，形成符合Norsok標(biāo)準(zhǔn)的巖石間的屏障。利用該系統(tǒng)，可在不到兩天時(shí)間內(nèi)布置巖石間的屏障，目前該技術(shù)可用于單層套管與雙層套管井。

HydraWell業(yè)務(wù)開發(fā)副總裁Arne G. Larsen說：“令人印象深刻的是，Aker BP公司是如何不遺余力地在作業(yè)時(shí)間、HSE以及成本方面取得進(jìn)步的。我們引以為豪的是為這項(xiàng)偉大的工作貢獻(xiàn)了技術(shù)與知識(shí)。PWC系統(tǒng)降低了每一次封堵作業(yè)的成本、HSE風(fēng)險(xiǎn)，減少了對(duì)環(huán)境的影響，因此我們認(rèn)為，我們的技術(shù)符合Aker BP的雄心壯志，是最佳拍檔?！?/p>

據(jù)英國(guó)石油天然氣管理局估計(jì)，井筒的棄置封堵費(fèi)用約占井筒開發(fā)總成泵的 48% (根據(jù)英國(guó)石油天然氣管理局的數(shù)據(jù))，而井況復(fù)雜的井筒作業(yè)成本更是接近數(shù)千萬美元，而且這是一項(xiàng)不會(huì)帶來收入的作業(yè)，讓人非常頭疼。

一些公司希望減輕這種痛苦，開發(fā)出類似熱固性封堵方案以及等離子體鉆進(jìn)技術(shù)。挪威的Hydrawell公司是PWC領(lǐng)域的先行者。該公司的PWC解決方案包括一套工具，能夠幫助作業(yè)者降低需要分段磨銑的封堵棄井的成本，從大約10-14天的工期兩天的一趟鉆即可完成該項(xiàng)作業(yè)。

據(jù)悉，Aker BP公司正評(píng)估其最新工具組合的無鉆機(jī)版本，以進(jìn)一步降低成本，同樣，該公司也在評(píng)估新的屏障驗(yàn)證技術(shù)，避免為了重新測(cè)井，重新鉆進(jìn)剛布置的水泥屏障。開發(fā)HydraHemera系統(tǒng)是為了能夠在多個(gè)環(huán)空中封堵油井，且無需執(zhí)行分段磨銑作業(yè)。

HydraHemera系統(tǒng)由兩個(gè)部件組成，HydraHemera噴射工具與HydraHemera注水泥工具。HydraHemera噴射工具用于清洗與清除套管射孔殘留在環(huán)空中的碎片，它具有多個(gè)噴嘴，定位在不同的角度，并設(shè)計(jì)成最優(yōu)配置與噴射流速。這些射流可穿透并徹底清洗多層已射孔的套管。

在封堵材料注入截面前，HydraHemera噴射工具可確保套管環(huán)空處于最佳狀態(tài)。碎屑、舊泥漿、重晶石以及舊切屑被干凈的泥漿取代。射流清洗后利用投球機(jī)制，激活HydraHemera注水泥工具，并與HydraArchimedes工具結(jié)合，可將封堵材料置于多重環(huán)空的橫截面內(nèi)，從而在井中建立適當(dāng)?shù)钠琳?，用于封堵棄井或?cè)鉆作業(yè)。

再具體應(yīng)用中，完成一趟射孔后，會(huì)在目標(biāo)區(qū)域留有大尺寸的射孔孔眼，然后將HydraHemera下至井中射孔段的頂部。HydraHemera Bull Nose可實(shí)現(xiàn)下入時(shí)的循環(huán)。投球后，激活清洗噴嘴。泵入清潔泥漿，從HydraHemera中噴出高能量射流，徹底清潔兩層套管后的環(huán)空。第二次投球?qū)⒓せ頗ydraHemera注水泥工具中的水泥噴嘴，該工具擁有針對(duì)水泥優(yōu)化的過流面積。在鉆具組合旋轉(zhuǎn)的同時(shí)泵送水泥，并利用HydraArchimedes工具將水泥有效地注入中間與外部環(huán)空中。

技術(shù)特點(diǎn)：

Through utilization of the PWC (Perforate, Wash & Cement) plug and abandonment method (P&A) on the Valhall field, HydraWell has contributed towards Aker BP executing its plugging program significantly quicker than planned.

Since May 2017, HydraWell has contributed towards plugging 10 shut-in wells on the original drilling platform (DP) at the Valhall field center.

Compared to the first P&A phase on the DP platform from 2014 to 2016, Aker BP has reduced the average time per well by 50% in the latest phase, despite a rise in the complexity of the wells towards the end of the campaign.

Plugging wells on the DP platform is a key part of the work to modernize the Valhall field center. The three original platforms from when the field started producing in 1982 – QP, DP and PCP – will be removed. Four wells remain to be permanently plugged prior to the removal of the DP platform.

“We have significantly reduced the execution time of our P&A operations through improving a number of elements. HydraWell’s PWC technology, with HydraHemera in front, is one such element. Among other things, we have run computer simulations to identify how much time we need to wash the back of the casing before the cementing starts. This has improved our understanding and means that we can do things faster than before,” says Martin Straume, drilling engineering manager plugging and abandonment, Aker BP.

“In addition, together with HydraWell we have started running one-trip systems on applicable wells. This means that we drop the perforation gun into the well instead of pulling it back up before we start washing. This has contributed towards reducing execution time significantly,” Straume adds.

HydraWell’s HydraHemeraTM PWC system perforates the well before washing the casing and then setting the cement plug – a so-called rock-to-rock barrier that is required under the Norsok standard. Through this method a rock-to-rock barrier can be installed in less than two days. The technology can be utilized on both single and dual casing wells.

“It is impressive to witness how Aker BP leaves no stone unturned to identify improvements with regards to execution time, HSE and costs. We are proud to contribute with technology and knowledge towards this work. PWC reduces both costs, HSE risks and the environmental footprint of each plugging operation, so we feel that we are a good match for Aker BP’s ambitions,” says Arne G. Larsen, HydraWell’s vice president of business development.

Amounting to an estimated 48% of decommissioning costs (according to the UK’s Oil and Gas Authority) and with “train wreck” wells costing nearly double-digit million dollar figures, it’s an activity that brings in no revenues, just headaches.

There are firms looking to ease the pain, developing the likes of thermite plug solutions and plasma drilling technology. Something less exotic is starting to make in-roads into the P&A space, however: perforate, wash and cement (PWC) tools and methodologies. Norway’s Hydrawell was a first mover in the PWC space. The firm’s PWC solutions comprise a suite of tools helping to cut well P&A cost, where section milling would have been required, from ca.10-14 days to just two, when run as a one-trip solution.

The firm is assessing options for a rigless version of its latest tool portfolio, to further reduce costs, as well as technologies for barrier verification, without having to redrill the just installed barriers – for re-logging.

The HydraHemera? system was developed to enable plugging a well across multiple annuli without performing a section milling operation.

The system consists of two components, a HydraHemera? Jetting Tool and a HydraHemera? Cementing Tool. The HydraHemera? Jetting Tool is used to wash and clean out debris in the annuli behind perforated casings. It features jet nozzles which are positioned at irregular angles and engineered for optimum configuration and exit velocity. The jets penetrate and clean thoroughly behind multiple perforated casings.

The HydraHemera? Jetting Tool ensures optimum conditions in the casing annuli prior to placing the plugging material in the cross section. Debris, old mud, barite and old cuttings are replaced by clean mud.

Using a ball drop mechanism after jetting, the HydraHemera? Cementing Tool is activated, and combined with the HydraArchimedes? tool enable placing plugging material in the entire cross section of multiple annuli, and hence, establishing a proper barrier in the well for P&A or sidetrack purposes.

OPERATION: After completing a perforating run with big hole charges in the target zone, the HydraHemera? system is run in hole to the top of the perforated section. The HydraHemera? Bull Nose allows for circulation while running in hole. A ball is dropped which activates the cleaning nozzles. Clean mud is pumped which exits the HydraHemera? as high energy jets, thoroughly cleaning behind up to two casing strings. A second ball drop activates the cementing nozzles in the HydraHemera? Cementing Tool, which feature flow area optimized for cement. Cement is pumped while rotating the assembly, and the cement is placed efficiently into the intermediate and outer annuli utilizing the HydraArchimedes? tool.

FEATURES/BENEFITS: · One trip plugging system · No milling required · Allows full flow when tripping in and out · Simple design and operation · Ideal for cleaning single and multiple annuli · Available for all casing sizes

備注：數(shù)據(jù)僅供參考，不作為投資依據(jù)。