Addressing Wellbore Position Challenges in Ultra-Extended-Reach Drilling in Russia's Far East

Poedjono, Benny; Rawlins, Sheldon Andre; Singam, Chandrasekhar Kirthi; Tweel, Alexander Van Den; Dubinsky, Alexey; Rakhmangulov, Rustam; Maus, Stefan

doi:10.2118/160784-ms

Cited by 10 publications

(1 citation statement)

References 3 publications

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“…Wells are considered as extended-reach wells (ERWs) when their horizontal displacement (HD) to true vertical depth (TVD) ratio are higher than 2.0 [1,2]. In recent years, the extended-reach wells envelope is continuously expanded (see Figure 1), and now it is not surprising to drill extended-reach wells with HD to TVD ratio greater than 6.0 or with HD longer than 30,000 ft [3][4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

The Maximum-Allowable Well Depth While Drilling of Extended-Reach Wells Targeting to Offshore Depleted Reservoirs

et al. 2018

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In depleted offshore reservoirs, pore pressure declines and consequently horizontal in-situ stresses decrease as well. This causes a very limited well depth for extended-reach drilling targeting to offshore depleted reservoirs. In this paper, based on analyzing the safe mud weight window of the depleted offshore reservoirs, a model of predicting the Maximum Allowable Measured Depth (MAMD) for extended-reach drilling targeting to offshore depleted reservoirs is developed. Meanwhile, the numerical method of the model is proposed, and the key affecting factors of the MAMD are also investigated. The results show the pore pressure depletion has obvious effects on the MAMD. With the depletion of pore pressure, the safe mud weight window appears narrower and even disappears, consequently the predicted MAMD becomes shorter. For a normal regime depositional environment in the depleted reservoirs, it may be impossible to drill with conventional drilling method in the nearby directions of the maximum horizontal in-situ stress, while it may be much safer and attain a long MAMD when drilling in the directions near the minimum horizontal in-situ stress. Moreover, the MAMD will decrease with the increase of Poisson's ratio and Biot's parameter, and its response to Poisson's ratio is more obvious. For a specific target depleted reservoir, the extended-reach drilling with a high borehole inclination may have a longer MAMD than that with a low borehole inclination. This paper presents a method for promoting the design of extended-reach drilling targeting to offshore depleted reservoirs.

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Section: Introductionmentioning

confidence: 99%

The Maximum-Allowable Well Depth While Drilling of Extended-Reach Wells Targeting to Offshore Depleted Reservoirs

et al. 2018

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Enhanced Magnetic Surveying Technique Allows Tight Target Requirements to Be Achieved While Maintaining Drilling Efficiency

Aziz

Mondali

Mohammad

et al. 2013

SPE Asia Pacific Oil and Gas Conference and Exhibition

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Enhanced Magnetic surveying technique was introduced to Field Q in Malaysia allowing the tight geological target requirements to be achieved without impacting the operator’s drive for drilling efficiency. Managing wellbore uncertainty is a significant challenge in Field Q, West Malaysia, where the Subsurface Team defines tight reservoir targets to accommodate the uncertainties that they have in a long step out well. Accurate well positioning becomes crucial in this situation to allow the penetration of multiple small targets. Historical approaches would have involved either running gyro surveys (which introduce more risk and time to the drilling process), or having to "over engineer" the wells (by creating tortuous well paths and drilling on the line to achieve the small drilling targets) due to the uncertainties of standard MWD surveys. Both of these approaches are against the drive to continually improve drilling efficiency while reducing risks. Magnetic surveying has become increasingly accurate and now provides a cost-effective alternative to gyroscopic surveys in real-time drilling applications. New techniques for identifying and compensating for these errors involve a better understanding of the natural variations in the earth’s magnetic field, and new methods of mapping local variations improve magnetic modeling. The enhancement involves a multi-station analysis technique that provides compensation for drillstring magnetic interference and further improved when used in conjunction with geomagnetic referencing, which takes account of localized crustal effects in the earth’s magnetic field. With a Geomagnetic Referencing System in Field Q, magnetic survey reduced uncertainty by 60% on average compared to a standard MWD error model. The benefits from this real-time drilling surveying process also means drilling is more accurate, with a reduced need for correction runs, or post-drilling changes to the planned well trajectory.

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Accurate Geometric Well Placement of the First ERD Producer Well Drilled From the Artificial Island in UAE

ElGizawy

Grini²,

Junaibi³

et al. 2014

Abu Dhabi International Petroleum Exhibition and Conference

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Accurate wellbore geometric placement is fundamental to achieve the objective of maximizing hydrocarbon production and recovery. It is especially essential in real time to drill complex 3D well trajectories that penetrate multiple thin geological targets. Accurate placement is also critical to avoid catastrophic subsurface collision of nearby offset wells. This is critical in particular in this gigantic field with over 800 wells drilled by two different operators with several hundreds more wells to follow. Almost all Bottom Hole Assemblies (BHA) run in this field include a Measurement-While-Drilling (MWD) survey tool to survey the wellbore while drilling. The MWD is a magnetic survey tool that is subject to errors that limit the magnetic survey accuracy. One of the main sources of error is the variation in the local magnetic field due to the crustal anomalies in this field. The magnetic surveys can provide an accurate geometric well placement by incorporating the knowledge of the local magnetic field disturbance to the main geomagnetic field model and by compensating for the drill-string magnetic interference. The Geomagnetic Referencing Service (GRS) technique based on magnetic surveys was introduced in this field. This technique utilizes the local magnetic data that is measured over the field by acquiring a high-definition airborne gravity and magnetic survey. The accuracy of the geometric well trajectory of the first oil producer well is compared between the MWD, cased gyroscopic and GRS surveys and the advantage of the GRS is presented. The benefits of applying GRS in real-time while drilling is paramount, where it provides an accurate well position in real time when corrections to the well trajectory are still possible. It prevents the costly sidetracks if the post drilling gyroscopic survey shows the well has missed its target. In most cases, GRS is an alternative to the gyroscopic surveys where it provides magnetic survey accuracy that is comparable to the casing gyroscopic survey tools. Hence, it saves the cost and risk of running gyroscopic survey tool as well as the cost of the extra rig time required to run a gyroscopic tool after drilling.

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Addressing Wellbore Position Challenges in Ultra-Extended-Reach Drilling in Russia's Far East

Cited by 10 publications

References 3 publications

The Maximum-Allowable Well Depth While Drilling of Extended-Reach Wells Targeting to Offshore Depleted Reservoirs

The Maximum-Allowable Well Depth While Drilling of Extended-Reach Wells Targeting to Offshore Depleted Reservoirs

Enhanced Magnetic Surveying Technique Allows Tight Target Requirements to Be Achieved While Maintaining Drilling Efficiency

Accurate Geometric Well Placement of the First ERD Producer Well Drilled From the Artificial Island in UAE

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