helmerich&payne_blog

The footage drilled with rotary steerable systems (RSS) has increased significantly these last few years, due notably to the highly complex wells drilled today. Moreover, high requirements about borehole quality are needed to optimize drilling performances , running completion tools or increase the quality of formation evaluation. Rotary steerable systems can be classified in two types according to the steering mechanism: point-the-bit and push-the-bit. Whatever the type of steering mechanism , both tilt and side force are applied on the bit. Although bit tilt is predominant in point-the-bit system, bit side force is the main factor that affects hole deviation in push-the-bit system. There have been many controversies in the scientific and industrial community regarding the deviation mechanisms involved in these two systems. To react to this controversy, a full-scale drilling bench has been developed to test drill bits in push-the-bit, point-the-bit or hybrid push-point mode. This new...

Axial force transfer is an issue in deviated wells where friction and buckling phenomenon take place. The general perception of the industry is that once drill pipe exceeds conventional buckling criteria, such as Paslay Dawson, axial force cannot be transferred down-hole anymore. This paper shows that, even though buckling criteria are exceeded, axial force transfer could be still good if drill pipe is in rotation. On the contrary, there exists sliding operations where lockup is observed, due to buckling, even though standard buckling criteria are not exceeded. This paper is intended to show and explain how axial force is transferred down-hole in many simulated field conditions: sliding, rotating, with or without dog legs. These new results have been obtained from an advanced model dedicated to drill string mechanics successfully validated with laboratory tests. This paper will show applicable results for practical well operations where axial force transfer is an issue. The applica...

When drilling complex wells , such as those with long lateral sections, the friction forces become significantly high, which can impede advancement of the drill string and reduce drilling performance . In these situations, Axial Oscillation Tools (AOT) could be used to introduce an axial vibration to the drillstring. By locally reducing the friction forces, better transmission of weight to the drill bit is possible and an increase in the rate of penetration occurs. However, to optimize the use of these tools, predictive modeling is necessary to assess their effect on drilling characteristics . A new modeling approach is proposed to accurately model the effect of the AOT on drilling operations without the need to carry out resource-intensive and time-consuming dynamic computations. To estimate the influence length (i.e. the extent of the axial vibrations) and the maximum displacement at the AOT, a study was performed to determine the most important parameters. Based on this study and ...

The drilling industry has substantially improved performance based on knowledge from physics-based, statistical, and empirical models of components and systems. However, most models and source code have been recreated multiple times, which requires significant effort and energy with little additional benefit or step wise improvements. The authors propose that it is time to form a coalition of industry and academic leaders to support an open source effort for drilling , to encourage the reuse of continuously improving models and coding efforts. The vision for this guiding coalition is to: 1) Set up a repository for source code, data, benchmarks, and documentation. 2) Encourage good coding practices. 3) Review and comment on the models and data submitted. 4) Test, use and improve the code. 5) Propose and collect anonymized real data. 6) Attract talent and support to the effort. 7) Mentor those getting started. Those interested to add their time and talent to the cause may publish their ...

Standard directional surveying practices are subject to numerous error sources which can cause inaccurate placement of the wellbore. This is problematic because inaccurate wellbore placement increases collision risk, reduces reservoir drainage, and impacts subsurface models. Web-based software was developed to provide rig site personnel with a simple interface to transfer survey data in real-time to survey analysts in a remote operations center. The web interface is easily accessible via standard web browsers and enables users to upload data in any format without the need to manually configure or manipulate data fields. Independent survey quality analysis by remote operating centers is the most effective way to validate directional survey accuracy and to ensure it is free from gross or large systematic errors that exceed the assumptions of the positional error model. Furthermore, by applying multi-station analysis corrections and using in-field referencing geomagnetic models, the pos...

Optimizing lateral well spacing is a challenging problem that has significant economic consequences. The intent is to drill the fewest number of horizontal wells that will effectively maximize reservoir drainage. Successful field development requires spacing horizontal wellbores at an optimum distance that minimizes overlapping drainage areas without stranding reserves. There are many variables that must be considered when determining lateral spacing such as hydraulic fracture geometry and reservoir properties. However, a variable that is often overlooked is wellbore positional uncertainty. It is common to ignore the contribution that inaccurate directional surveying has on lateral wellbore spacing. The purpose of this paper is to demonstrate how inaccuracy in standard directional surveying methods impacts wellbore position and to recommend practices to improve surveying accuracy for greater confidence in lateral spacing. Standard directional surveying by measurement while drilling (...

Finding an optimal lateral spacing is crucial to maximizing the return on investment for unconventional assets. The estimates regarding these lateral spacings were made for various plays; however, in a general sense, they assumed that the wellbores were precisely drilled and surveyed (Bharali et. al., 2014; Lalehrokh & Bouma, 2014). Wellbore positions have potentially large uncertainties and recent studies demonstrate that these uncertainties are even larger than previously assumed (Love, et. al, 2020).This study combines the previous work completed on spacing uncertainty with a reservoir simulation model to better quantify the losses caused by positional uncertainty, while exploring the sensitivity of said losses in relation to the changing lateral length, well spacing and survey accuracy allowing for future optimal field development. A previous method of simulating reservoir losses due to survey uncertainty, proposed by Maus & DeVerse (2016) and the major basins reservoir s...

  IFR models are computed from high-resolution satellite and aeromagnetic measurements of the geomagnetic field. A new constellation of low-orbiting satellites provides accurate specification of the long-wavelength geomagnetic field. This information is complemented by local high-resolution airborne magnetic surveys . Once the natural geomagnetic field is accurately specified by IFR, magnetic interference from the drill string can be removed by the Multi-Station correction. This paper highlights the benefits of IFR and MS corrections on specific examples from Texas and North Dakota. Azimuth corrections of 1 degree lead to changes in wellbore position of 200 feet and more at TD. Improved specification of the strength and dip of the geomagnetic field further enables tighter quality control of MWD surveys. The improved accuracy of the IFR+MS technique is quantified in the new set of Operator Wellbore Survey Group (OWSG) tool code MWD+IFR+MS. This tool code reduces ellipses of uncert...

Positional uncertainty is a critical component of managing collision risk while drilling. Ensuring that survey data meet the requirements of their uncertainty models has historically required complicated analysis. Most consumers of  survey data  are not experts and knowing when escalation is required in a high-risk situation can be unclear. This problem will increase as more data is evaluated by automated decision-making systems. Two novel methods are proposed to analyze sets of survey data against uncertainty models with the intent to answer the questions: "Is it safe to continue drilling" and "Does this wellbore need to be resurveyed?". The proposed methods evaluate a survey set using the error sources, error magnitudes, and error propagations contained in positional uncertainty models. A quality control error covariance matrix is constructed, and the set is evaluated against it. Two statistical outputs are generated: a statistical distance that explains how well ...

Drilling ultra-extended-reach (ultra-ERD) wellbores has redefined industry standards. Operators and service companies must fully assess the accompanying risks to maximize the overall productivity of an asset. New drilling technologies, such as improved drilling fluid design and geomechanics analyses, allow wellbores to be drilled to the lateral displacement of greater than 13 km. This requires improved absolute  wellbore positioning , in conjunction with reduced uncertainties. When developing these  drilling technologies , the economics must be considered so as not to exponentially increase the cost per barrel of oil. The increase in infill drilling of nearby offset wellbores requires developing improved methods that reduce  wellbore position  uncertainty when placing the wellbore in the reservoir, in addition to avoiding collisions. The proposed geomagnetic referencing technique is suitable for the application to the Sakhalin-1 project in eastern Russia. Here there ...

As development of the Barents Sea continues with new plays such as the Castberg, accurate specification of the local magnetic field is important to reliably infer the orientation of the bottomhole assembly (BHA) in horizontal drilling. Since magnetic fields at high latitudes vary spatially and temporally, one requires both spatial models and a way to capture temporal changes. Large temporal changes in the magnetic field can severly distort measured azimuths and therefore must be corrected for. This study, based on a report written for Petroleumstilsynet (Maus et al., 2017), shows that in regions of the Barents Sea within 50 km of a magnetic observatory, either the nearest observatory, interpolated infield referencing (IIFR), or the disturbance function (DF) method may be used for corrections in  wellbore surveying  to meet accuracy requirements. IIFR and DF will give better error reduction but are slightly more complicated to implement. At distances between 50 km and 250 km, t...

Wellbore trajectories  are a fundamental piece of data used for decisions throughout the oilfield. Trajectories are typically mapped through  measurement-while-drilling (MWD)  survey stations collected at 95ft intervals. Previous work suggests that this sparse sampling interval masks short segments of high curvature, negatively impacting workflows that consume this data (Stockhausen & Lesso, 2003; Baumgartner, et. al., 2019). This can come in the form of poorly estimating the true vertical depth of a well, poorly mapping geologic structure, and poorly quantifying the tortuosity of the wellpath. Several methods have previously been proposed to improve trajectory mapping by incorporating additional data collected between stationary surveys (Stockhausen & Lesso, 2003; Gutiérrez Carrilero, et al., 2018). Two sources of such data are continuous survey measurements and slide/rotate behaviors captured in slide sheets. Two methods of improving the  wellbore trajector...

Lateral spacing in unconventional plays can have a significant impact in the economics of field development (Bharali et al., 2014; Lalehrokh & Bouma, 2014). This spacing is most often verified using magnetic measurement while drilling (MWD) instruments. In well spacing studies, the distance between two laterals is typically assumed to be precise, however, MWD may have large uncertainties associated with their bottom hole locations (Williamson, 2000; Grindrod et al., 2016). Standard error models were built primarily using data from major service providers' offshore operations and assume a level of accuracy that may not reflect current practices for onshore drilling in North America (Love, 2019). This study better quantifies the positional uncertainties of MWD surveys in long laterals and uses those uncertainties to estimate well spacing uncertainty. More than 35,000 MWD bit runs across more than 9,000 laterals wellbores in major basins across North America have been analyzed for...

In the current drilling climate, efficiency is king: do more with less. This motivation drives disruptive technological innovations in automation of the drilling process. Drilling automation can contribute to this efficiency specifically by automating the sliding process. The paper discusses a case history involving one operator's deployment and results of an automated sliding system. The goal for automating the sliding process was to reduce personnel on location, drive consistency, increase wellbore quality, and shift the focus from an ROP-focused mindset. The operator had initially used bit guidance software for approximately one year, which was a significant backbone component of the automated sliding system. The automated sliding software was installed and tested on the rig, and then deployed on a six-well pad for initial observation and analysis. After deployment, the automated sliding system successfully completed slides in all four surface sections on the pad. The first comp...

Efficient drilling through heterogenous geology requires careful matching of drilling parameters to the rock being drilled. Failure to do so can lead to increased bit damage or poor drilling performance. The "driller's roadmap" is a list of such parameters to be changed at various depths where formation tops are expected to be crossed. Successful execution of these roadmaps relies on having a detailed geological prognosis of where specific formations will be encountered. When drilling the first well on a pad, the precise depths of geological boundaries may be unknown preventing successful roadmap execution. By providing a feedback loop between a driller's roadmap and an automated formation top detection algorithm, it is possible to identify and proactively respond to geology even when drilling in these uncertain conditions. A roadmap was created with target drilling parameters for each formation that would be encountered when drilling. Critical formations were identif...

In the today high-cost and complex drilling environment, the importance of drillstring failure issue has dramatically reappeared, in spite of many manufacturing and materials improvements. Most drillstring failures are due to fatigue, resulting from repeated cyclic bending loads and stresses in tensile or buckled drill pipes. Fatigue prediction is usually based on the cumulative fatigue damage model from Hansford and Lubinski as defined in API RP7G. This model, based on S-N curves, a failure criterion and a damage accumulation rule, initially requires a calculation of the drillpipe stress caused by bending when rotated in a dog leg. This bending stress calculation, key point of the cumulative fatigue damage model, is usually made by assuming that the curvature of the drill pipe is the same as the dog leg. However, this paper shows that this strong hypothesis may lead to major under-estimation of the cumulative fatigue damage. Moreover, the stress distribution within a drill pipe may be...

Whether you’re on a rig, in a vehicle, or in an office, safety always comes first. The expectation is a culture focused on safety and environmental stewardship. Each year as we build out actionable goals for the year ahead, a team is dedicated to setting the goals, communicating the expectations, and holding teams accountable – with the intent of delivering quality, meaningful results. Goals At H&P, our Safety Leadership Team (SLT) is comprised of representatives across multiple departments and all business units. Their multidisciplinary perspective uniquely qualifies the group to have a direct influence on controlling and removing serious injury or fatality (SIF) exposures at H&P locations around the world. By analyzing HSE data, reports, and feedback from field operations, the SLT uses this critical information to establish H&P’s Actively C.A.R.E. Goals for the upcoming year. Once the prioritized safety and environmental goals are set, cross-functional steering teams ar...