Drilling Tools: Managed Pressure Drilling Systems That Measure Loss of Circulation in Real Time

Drilling Tools: Managed Pressure Drilling Systems That Measure Loss of Circulation in Real Time

钻井工具：实时计量循环漏失的控压钻井系统

口Yu Fenglong / Compilation

口于凤龙／编译

Most of the easy blocks have been produced, while existing oil and gas resources are complex to develop due to their narrow operating windows created by pore pressure gradients and fracture pressure gradients. This makes drilling complex and difficult to control. Weatherford's Managed Pressure Drilling systems make previously un drillable. It is the only fully automatic throttling system in the industry, which can monitor the changes of wellbore pressure and flow in real time and respond in time. It has a revolutionary change in the accuracy and analysis precision of wellbore pressure and flow measurement.

大多数容易的区块都已开采，而现有的油气资源由于其孔隙压力梯度和破裂压力梯度所构成的作业窗口很窄，所以开发起来很复杂。造成了钻井的复杂性且难于控制。威德福的控压钻井系统能使之前的不可钻井变为可钻井。它是行业内唯一的全自动节流系统，能实时测虽井筒压力和流量变化并及时作出反应，在井筒压力和流量计量的准确性和分析精度方面具有革命性的变革。

By using micro-flow control technology, the system uses unique algorithms to determine and measure minute down hole overflows and losses in real time. The return flow rate is measured using a high-precision flow meter installed on the throttling line to detect fluid loss or increase in liquid level as early as possible, and automatically respond to reduce the amount of fluid increase or decrease in volume. Make critical drilling decisions based on actual wellbore information rather than relying on predictive models. Combining closed-loop technology and cutting-edge unique data acquisition and computer control equipment, the system can improve drilling rig safety and drilling efficiency to a level that cannot be achieved by conventional drilling or even other managed pressure drilling.

通过运用微流量控制技术，该系统使用特有的算法能实时判断并测量微小的井下溢流和漏失。使用安装在节流管线上的高精度流量计测量返出流速，从而尽早发现流体漏失或液面增加，并自动作出反应，从而降低流体增加或减少的体积量。根据实际井筒信息作出关键的钻井决策而不是依赖预测模型。综合运用闭路循环技术和尖端的独有数据采集和计算机控制设备，该系统能使钻机安全和钻井效率提高至常规钻井，甚至其它控压钻井所无法达到的高度。

Managed pressure drilling systems rely on their ability to precisely control wellbore pressure to help accomplish drilling goals and overcome challenges that conventional drilling has been unable to solve for many years. While greatly improving the flexibility and safety of drilling operations, operation risks and non-productive time are minimized.

控压钻井系统依靠其精确控制井筒压力的能力帮助完成钻井目的，并克服常规钻井多年来无法解决的难题。极大地提高了钻井作业的灵活性和安全性的同时，尽可能降低了作业风险和非生产时间。

A number of factors make drilling in a Middle East oilfield extremely difficult, including formations containing a large amount of unstable porous limestone and high hydrocarbon-bearing sandstone, inter bedded with shale inter beds that tend to expand. In general, this will result in a large amount of mud leakage, with the risk of sticking and fishing. High pressure shallow gas takes a long time to circulate out of the well, creating a lot of non-productive time.

诸多因素使某中东油田极难钻井，包括含有大量不稳定孔洞性石灰岩和高含烃砂岩地层，其间还夹杂着页岩互层，趋于膨胀。一般来讲，这将造成大量的泥浆漏失，并有卡钻和落鱼风险。高压浅层气需要很长时间才能循环出井，从而产生大量的非生产时间。

In addition, the narrow window of pore pressure and fracturing pressure gradient can cause flooding, causing well control problems and leading to wellbore instability, as long as the equivalent circulating density drops slightly during a single tap. If higher density mud is used to prevent overflow, the formation will be fractured, causing problems such as circulation loss, formation damage, differential pressure sticking and low ROP. Practice has proven that this narrow gradient window cannot be penetrated with conventional drilling.

此外，在接单根时，只要当量循环密度稍微下降，孔隙压力和破裂压力梯度构成的窄窗口即能引起溢流，从而引起井控问题，并导致井眼不稳定。若用密度较高的泥浆防止溢流，则会压裂地层，造成循环漏失、地层破坏、压差卡钻和机械钻速低等问题。实际作业已证明，用常规钻井无法穿穿该窄梯度窗口。

The use of secure managed pressure drilling system can effectively solve the above problems. Install a circulating device socket on each column to ensure continuous circulation when the drill pipe is connected. The Secure Drilling System accurately monitors annular back pressure and maintains it within a narrow drilling window. The construction of this well shows that the drilling system can detect and control the overflow less than 1.5 barrels within two minutes.

采用secure控压钻井系统可以有效地解决以上问题。在每一立柱上安装循环装置插孔，可以在接钻杆时保证继续循环。Secure钻井系统可以精确地监测环空回压，使其维持在窄钻井窗口之内。本井施工表明，该钻井系统能在两分钟之内监测发现并控制小于1.5桶的溢流。

The equipment used in managed pressure drilling includes: the rotating control head originally maintains a closed-circuit and pressurized drilling environment. Secure Micro-Overflow Control MPD equipment can monitor and control annular pressure and other drilling variables in real time. It includes an automatic throttle manifold. Back pressure can be adjusted as required by an automatically controlled auxiliary mud pump.

控压钻井所用到的设备包括：旋转控制头原来维持一个闭路带压的钻井环境。Secure微溢流控制控压钻井设备能实时监测，并控制环空压力和其它钻井变量参数。它包括一个自动节流管汇。根据需要，可以通过一个自动控制辅助泥浆泵来调节回压。

In this area, the operator once drilled an exploratory well. The well was abandoned at 11,484 feet (3,500 meters). Later, by using a slightly underbalanced mud system, the well team and Weatherford technicians maintained fluid circulation, controlled annular pressure and bottom hole pressure, and successfully drilled the complex lower section, and achieved an 8.2 ft/h (2.5 m/h) h) The average ROP. The Secure drilling system was very successful in this operation, producing no unproductive time, no overflow, and no leakage. On top of that, operators can keep drilling at up to 50 percent gas content.

在该地区，作业者曾经钻过一口探井。该井在11484英尺（3500米）处弃井。后来，井队和威德福技术人员通过使用微欠平衡泥浆体系，维待流体循环，控制环空压力和井底压力，成功钻完下部复杂井段，并取得8.2英尺/小时（2.5m/h）的平均机械钻速。Secure钻井系统在本次作业中非常成功，没有产生非生产时间，无溢流，无漏失。除此之外，作业者在含气量高达50%的情况下还能保持钻进。

During the drilling process, the Secure Drilling System monitored two losses, followed by overflow after two losses, and then again. All three overflows were monitored and circulated out of the wellbore with no impact on drilling.

在钻井过程中，Secure钻井系统监测到两次漏失和漏失之后的溢流，接着再次监测到溢流。三次溢流都被监测到并循环出井眼，没有对钻井产生影响。

Operators are very satisfied with the results. Because there is no non-productive time during managed pressure drilling, drilling can be maintained even with gas content as high as 50%, preventing gas intrusion and other well control problems, preventing circulation loss and differential pressure sticking. Best of all, the drilling depth was a full 50% higher than what was previously possible.

作业者对结果非常满意。因为在控压钻井过程中没有产生非生产时间，气体含量高达50%的情况下还能保持钻进，防止了气侵和其它井控问题，防止了循环漏失和压差卡钻。最重要的是，钻井深度比以前所能钻深整整提高了50%。

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Keywords关键词：实时计量,循环漏失,控压钻井系统,孔隙压力梯度,破裂压力梯度,全自动节流系统,微流量控制技术,预测模型,非生产时间,压差卡钻,溢流,当量循环密度,自动控制辅助泥浆泵,微欠平衡泥浆体系,循环漏失,窄梯度窗口.

Real-time metering, loss of circulation, managed pressure drilling system, pore pressure gradient, fracture pressure gradient, automatic throttling system, micro-flow control technology, predictive model, non-production time, differential pressure sticking, overflow, equivalent circulating density, automatic Control auxiliary mud pump, slightly underbalanced mud system, circulation loss, narrow gradient window.

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Poster发布人:Clark Guo,CCSC Technology,Shanghai,China, 2022.09     Youtube: ClarkOilGas  

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