Advanced Wellbore Surveying Technology Extends the Drilling Limits in Offshore Operation

2021 ◽  
Author(s):  
Mahmoud ElGizawy ◽  
Knut Ness ◽  
Saleel Kolakkodan
Keyword(s):  
Real Time ◽  
Magnetic Measurement ◽  
Magnetic Survey ◽  
Well Placement ◽  
Hydrocarbon Production ◽  
Survey Tool ◽  
Close Proximity ◽  
Probability Of Collision ◽  
Measurement While Drilling ◽  
Bottom Hole Assembly

Abstract Wellbore surveying is critical while drilling in order to assure the drilled well is following the plan and is penetrating the geological target. Additionally, wellbore surveying is the key to allowing a well to be drilled safely, avoiding other wells drilled in the same field, and optimizing reservoir production. Standard wellbore surveying accuracy is increasingly inadequate for optimizing the well placement in real time to maximize the reservoir recovery due to maturity of the field. The other disadvantage of the standard wellbore surveying often requires running an additional wellbore surveying tool to improve the accuracy in order to manage the collision avoidance with nearby wells in the same field, introducing unwanted time and costs. Hence, this article presents the advanced wellbore surveying technology that is successfully implemented in offshore fields of Abu Dhabi to overcome the limitations of the standard surveying accuracy without compromising rig time. Magnetic measurement while drilling (MWD) surveys are common standard and utilized in every directional well in this operation. To overcome the standard accuracy limitation, advanced survey correction to the magnetic MWD surveys is introduced. This includes in-field referencing to provide a higher resolution magnetic reference to calculate a more accurate well direction, correction to the effect of the steel components in the bottom hole assembly on the magnetic MWD surveys, correction to the errors associated with survey sensors calibration, and correction to any misalignment between the survey tool and the wellbore. Correcting the surveys in real-time while drilling is the key to placing the well accurately and to avoid offset wells in the close proximity. The details of the corrections methodology are discussed. Advanced magnetic survey correction procedures in real-time are outlined and mapped out. Finally, results of improving the magnetic surveys while drilling in placing the wells and minimizing the collision risk of offset wells are presented. This advanced survey technology allows drilling previously un-drillable wells in these offshore fields, and the allowance for increased density of wells in the reservoir gives the operator opportunity to maximize production recovery and extend the life of reservoir. Higher accuracy of wellbore surveys is an increasing requirement in mature fields to safely allow more accurately placed wellbores with the required production rates. This allows for improved well placement along the trajectory facilitating adjustment at control points and landing points to maximize the hydrocarbon production. In addition, it allows controlling the probability of collision with any nearby wells. The enhanced wellbore surveying accuracy is achieved by advanced magnetic survey corrections in real time. This is controlled by a stringent novel process and communication protocol in order to meet the accuracy objectives.

Correcting Subsurface Seismic Depth Uncertainty in Real-Time Using Reservoir Navigation Distance-to-Bed Mapping

2021 ◽  
Author(s):  
Victor Imomoh ◽  
Kenneth Amadi ◽  
Johnbosco Onyeji
Keyword(s):  
Real Time ◽  
Gamma Ray ◽  
Drilling Process ◽  
Water Contact ◽  
Horizontal Drilling ◽  
The Earth ◽  
Measurement While Drilling ◽  
Bottom Hole Assembly ◽  
Petrophysical Data ◽  
Navigation Service

Abstract The most common challenge in horizontal drilling is depth uncertainty which can be due to poor seismic data or interpretation. It is arguable that a successful landing of the wellbore in the reservoir optimally and within the desired zone is the most challenging in most geosteering operation. The presence of fluid contacts such as oil-water-contact (OWC) and gas-oil-contact (GOC) complicates the whole drilling process, most especially if these fluid contacts are not well defined or known. Additionally, the ability to map the boundaries of the reservoir as the BHA drills the lateral section is an added advantage to remaining within the desired reservoir section. The success of any reservoir navigation service where seismic uncertainty at the reservoir top is high will rely largely on how effective the geosteering system is and how the geosteering engineer is able to react promptly to changes while landing the well in the reservoir and drilling the lateral section with without exiting the reservoir. Reservoir Navigation Service (RNS) provides the means for the drilling near horizontal or horizontal wells for the purpose of increasing hydrocarbon extraction from the earth's subsurface. This involves the use of a pre-defined bottom hole assembly (BHA) with inbuilt downhole logging while drilling (LWD) and measurement while drilling (MWD) sensors. The measurements from these downhole sensors are uplinked to the surface of the wellbore where they are converted to meaningful petrophysical data. The goal is to use the downhole petrophysical data such as gamma ray, propagation resistivity and so on, to update an existing pre-well geological model of a section of the earth in such a way that the final result depicts the true model picture of the earth subsurface. This paper focuses on using well CBH-44L to showcase how the use of real-time distance-to-boundary (D2B) measurement from a deep reading azimuthal propagation resistivity tool is use to correct for depth uncertainty in seismic, thereby, improving the chance of successfully landing and drilling a horizontal well.

Formation Evaluation From Logging on Cuttings

1998 ◽  
Vol 1 (03) ◽  
pp. 238-244 ◽  
Author(s):  
F.J. Santarelli ◽  
A.F. Marsala ◽  
M. Brignoli ◽  
E. Rossi ◽  
N. Bona
Keyword(s):  
Real Time ◽  
Large Scale ◽  
High Technology ◽  
Industrial Applications ◽  
S Wave ◽  
Instantaneous Rate ◽  
Formation Evaluation ◽  
Measurement While Drilling ◽  
Bottom Hole Assembly ◽  
High Degree

Abstract This paper presents an overview of a vast research project named Formation Evaluation 2000 that was undertaken by Agip SpA and was aimed at characterizing in real time the formations encountered during drilling by the mean of measurements on drill chips. To date, the project has demonstrated the feasibility to obtain representative values of the P and S wave velocities, rock strength and deformability, permeability, porosity, density, residual fluid content and saturation. Further work is underway in order to gain access to the pore size distribution, the thermal expansion and the conductivity of the rocks. The paper presents the methodology used systematically to assess such a feasibility and illustrates the results obtained to date during the various sequences of the research - i.e. primary design of the measure, laboratory tuning and field applicability. Furthermore, a series of field cases where these techniques were used are presented in order to highlight the industrial applications of such a package of measurements. Introduction In the oil industry, Formation Evaluation is traditionally performed after the drilling of the well by a series of techniques amongst which one can mention:core measurements which give direct indications but which are necessarily limited in space as it is often uneconomical to core continuously all the formations of interest;logs which give continuous measurements but which are often indirect - e.g. porosity from sonic logs;well tests of whatever nature - e.g. may they be for permeability determination or fracturation pressure, etc. - and which give large scale information about the rocks.In practice, the main drawback of such techniques is not so much technical than temporal in so far as they allow the characterization of the formations only after the end of the well whilst a while drilling evaluation would benefit many operations. For this reason, the industry has developed the Measurement While Drilling (MWD) and Logging While Drilling (LWD) techniques which aim at obtaining a real time formation evaluation. These techniques consist in inserting high technology sensors in the Bottom Hole Assembly and at performing and recording various measures on the formations soon after they have been discovered by the bit. Nevertheless, such techniques also suffer from various drawbacks which are listed below in a non-exhaustive manner: i. in the case when the measurement is sent directly from the bottom of the hole to the rig floor, the lag time for the availability of the information is only due to the distance between the bit and the sensor which may be several hours if the instantaneous Rate Of Penetration (ROP) is slow - e.g. < 2 m/h -; ii. in the case when the measurement is not sent to surface, the information only becomes available once the bit is pulled out of hole which may mean several days after the formations have been uncovered by the bit; iii. MWD and LWD tools are expensive high technology equipments which require a high degree of well stability to be run such as to minimize the risk of leaving them downhole because of a stick pipe problem. iv. finally, the interpretation of the measurements may be quite complicated as corrections have to be brought for various factors such as for example the vibrations of the drillstring in the case of the Sonic While Drilling. Because of the global situation described above, Agip decided to investigate the possible use of cuttings to perform quantitative physical determinations of the properties of the formations encountered by the well. As questions about the physical representativity of cuttings were raised very early in the project, it was decided to follow a two stage approach:

Integrating Images From Multiple Depths of Investigation and Quantitative Signal Inversion in Real Time For Accurate Well Placement

2008 ◽  
Author(s):  
Roland E. Chemali ◽  
Michael S. Bittar ◽  
Frode Hveding ◽  
Min Wu ◽  
Michael Raymond Dautel
Keyword(s):  
Real Time ◽  
Well Placement ◽  
Signal Inversion

scholarly journals Broccoli Fluorets: Split Aptamers as a User-Friendly Fluorescent Toolkit for Dynamic RNA Nanotechnology

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3178 ◽  
Author(s):  
Morgan Chandler ◽  
Tatiana Lyalina ◽  
Justin Halman ◽  
Lauren Rackley ◽  
Lauren Lee ◽  
...  
Keyword(s):  
Real Time ◽  
Logic Gates ◽  
Rna Aptamers ◽  
One Pot ◽  
Rna Nanotechnology ◽  
Close Proximity ◽  
Direct Tracking ◽  
Displacement Approach ◽  
User Friendly ◽  
In Cells

RNA aptamers selected to bind fluorophores and activate their fluorescence offer a simple and modular way to visualize native RNAs in cells. Split aptamers which are inactive until the halves are brought within close proximity can become useful for visualizing the dynamic actions of RNA assemblies and their interactions in real time with low background noise and eliminated necessity for covalently attached dyes. Here, we design and test several sets of F30 Broccoli aptamer splits, that we call fluorets, to compare their relative fluorescence and physicochemical stabilities. We show that the splits can be simply assembled either through one-pot thermal annealing or co-transcriptionally, thus allowing for direct tracking of transcription reactions via the fluorescent response. We suggest a set of rules that enable for the construction of responsive biomaterials that readily change their fluorescent behavior when various stimuli such as the presence of divalent ions, exposure to various nucleases, or changes in temperature are applied. We also show that the strand displacement approach can be used to program the controllable fluorescent responses in isothermal conditions. Overall, this work lays a foundation for the future development of dynamic systems for molecular computing which can be used to monitor real-time processes in cells and construct biocompatible logic gates.

Using Real-Time Pressure Data for Well Placement Planning

2006 ◽  
Author(s):  
Mike Parker ◽  
Robert N. Bradford ◽  
Laurence Ward Corbett ◽  
Robin Noel Heim ◽  
Christina Leigh Isakson ◽  
...  
Keyword(s):  
Real Time ◽  
Time Pressure ◽  
Pressure Data ◽  
Well Placement

A Novel Workflow for Geosteering a Horizontal Well in a Low Resistivity Contrast Anisotropic Environment: A Case Study in Semoga Field, Indonesia

2021 ◽  
Author(s):  
Yessica Fransisca ◽  
Karinka Adiandra ◽  
Vinda Manurung ◽  
Laila Warkhaida ◽  
M. Aidil Arham ◽  
...  
Keyword(s):  
Real Time ◽  
Horizontal Well ◽  
Gamma Ray ◽  
Lessons Learned ◽  
Electrical Anisotropy ◽  
Anisotropy Ratio ◽  
Well Placement ◽  
Low Contrast ◽  
Low Resistivity ◽  
The Subject

Abstract This paper describes the combination of strategies deployed to optimize horizontal well placement in a 40 ft thick isotropic sand with very low resistivity contrast compared to an underlying anisotropic shale in Semoga field. These strategies were developed due to previously unsuccessful attempts to drill a horizontal well with multiple side-tracks that was finally drilled and completed as a high-inclined well. To maximize reservoir contact of the subject horizontal well, a new methodology on well placement was developed by applying lessons learned, taking into account the additional challenges within this well. The first approach was to conduct a thorough analysis on the previous inclined well to evaluate each formation layer’s anisotropy ratio to be used in an effective geosteering model that could better simulate the real time environment. Correct selections of geosteering tools based on comprehensive pre-well modelling was considered to ensure on-target landing section to facilitate an effective lateral section. A comprehensive geosteering pre-well model was constructed to guide real-time operations. In the subject horizontal well, landing strategy was analysed in four stages of anisotropy ratio. The lateral section strategy focused on how to cater for the expected fault and maintain the trajectory to maximize reservoir exposure. Execution of the geosteering operations resulted in 100% reservoir contact. By monitoring the behaviour of shale anisotropy ratio from resistivity measurements and gamma ray at-bit data while drilling, the subject well was precisely landed at 11.5 ft TVD below the top of target sand. In the lateral section, wellbore trajectory intersected two faults exhibiting greater associated throw compared to the seismic estimate. Resistivity geo-signal and azimuthal resistivity responses were used to maintain the wellbore attitude inside the target reservoir. In this case history well with a low resistivity contrast environment, this methodology successfully enabled efficient operations to land the well precisely at the target with minimum borehole tortuosity. This was achieved by reducing geological uncertainty due to anomalous resistivity data responding to shale electrical anisotropy. Recognition of these electromagnetic resistivity values also played an important role in identifying the overlain anisotropic shale layer, hence avoiding reservoir exit. This workflow also helped in benchmarking future horizontal well placement operations in Semoga Field. Technical Categories: Geosteering and Well Placement, Reservoir Engineering, Low resistivity Low Contrast Reservoir Evaluation, Real-Time Operations, Case Studies

Implementation of Vendor-Independent Stochastic Inversion for Improving Quality and Efficiency of Well Placement on the Field of Novatek Company

2021 ◽  
Author(s):  
Danil Andreevich Nemushchenko ◽  
Pavel Vladimirovich Shpakov ◽  
Petr Valerievich Bybin ◽  
Kirill Viktorovich Ronzhin ◽  
Mikhail Vladimirovich Sviridov
Keyword(s):  
Real Time ◽  
Well Placement ◽  
Stochastic Inversion ◽  
Mathematical Algorithm ◽  
Service Companies ◽  
Resistivity Data ◽  
Resistivity Logging ◽  
Azimuthal Resistivity ◽  
Logging Tool ◽  
Single Approach

Abstract The article describes the application of a new stochastic inversion of the deep-azimuthal resistivity data, independent from the tool vendor. The new model was performed on the data from several wells of the PAO «Novatek», that were drilled using deep-azimuthal resistivity tools of two service companies represented in the global oilfield services market. This technology allows to respond in a timely manner when the well approaches the boundaries with contrasting resistivity properties and to avoid exit to unproductive zones. Nowadays, the azimuthal resistivity data is the method with the highest penetration depth for the geosteering in real time. Stochastic inversion is a special mathematical algorithm based on the statistical Monte Carlo method to process the readings of resistivity while drilling in real time and provide a geoelectrical model for making informed decisions when placing horizontal and deviated wells. Until recently, there was no unified approach to calculate stochastic inversion, which allows to perform calculations for various tools. Deep-azimuthal resistivity logging tool vendors have developed their own approaches. This article presents a method for calculating stochastic inversion. This approach was never applied for this kind of azimuthal resistivity data. Additionally, it does not depend on the tool vendor, therefore, allows to compare the data from various tools using a single approach.

Mobile autonomous methane monitoring stations for emission measurement

2021 ◽  
Vol 61 (2) ◽  
pp. 425
Author(s):  
M. Mainson ◽  
C. Ong ◽  
M. Myers ◽  
A. Spiers
Keyword(s):  
Real Time ◽  
Northern Territory ◽  
Emission Measurement ◽  
Fugitive Emissions ◽  
Gas Industry ◽  
Hydrocarbon Production ◽  
Code Of Practice ◽  
Emission Monitoring ◽  
The Government ◽  
Transmission And Distribution

Natural gas has been forecast to continue grow up to 30% for the next 40 years and will remain as a key energy source. Alongside this projected growth, both the government and the industry have committed to reduce emission reductions. A critical focus is fugitive emissions, which are related to leaks or unintended losses of methane from sources such as hydrocarbon production, processing, transport, storage, transmission and distribution. The need for measuring and monitoring these emissions has been recognised in significant environmental inquiries related to the gas industry, such as the Northern Territory Fracking Inquiry (Pepper et al. 2018) and required in section D of the NT Code of Practice. This study describes an autonomous emission monitoring station developed to address the challenge of characterising temporally varying fugitive methane emissions. It has been designed specifically to tolerate the Australian outback’s extreme climateswhile providing laboratory-grade measurements in real-time at locations where there will be no access to grid power and standard telecommunications. Preliminary results demonstrating the continuous real-time measurements of methane and ethane concentrations of temporally varying phenomena will be presented. Specifically, the detection of methane and ethane concentrations and temporal changes related to bushfire progress will be shown.

Utilizing NMR Workflow to Optimize Power Water Injector Placement in the Presence of Tar Barriers

2021 ◽  
Author(s):  
Gabor Hursan ◽  
Mohammed Sahhaf ◽  
Wala’a Amairi
Keyword(s):  
Spectral Analysis ◽  
Pore Size ◽  
Real Time ◽  
Total Porosity ◽  
Carbonate Reservoir ◽  
Wettability Alteration ◽  
Well Placement ◽  
Carbonate Formation ◽  
Fluid Saturation ◽  
Rock Quality

Abstract The objective of this work is to optimize the placement of horizontal power water injector (PWI) wells in stratified heterogeneous carbonate reservoir with tar barriers. The key to successful reservoir navigation is a reliable real-time petrophysical analysis that resolves rock quality variations and differentiates tar barriers from lighter hydrocarbon intervals. An integrated workflow has been generated based on logging-while drilling (LWD) triple combo and Nuclear Magnetic Resonance (NMR) logging data for fluid identification, tar characterization and permeability prediction. The workflow has three steps; it starts with the determination of total porosity using density and neutron logs, the calculation of water-filled porosity from resistivity measurements and an additional partitioning of porosity into bound and free fluid volumes using the NMR data. Second, the total and water-filled porosity, the NMR bound fluid and NMR total porosity are used as inputs in a hydrocarbon compositional and viscosity analysis of hydrocarbon-bearing zones for the recognition of tar-bearing and lighter hydrocarbon intervals. Third, in the lighter hydrocarbon intervals, NMR logs are further analyzed using a multi-cutoff spectral analysis to identify microporous and macroporous zones and to calculate the NMR mobility index. The ideal geosteering targets are highly macroporous rocks containing no heavy hydrocarbons. In horizontal wells, the method is validated using formation pressure while drilling (FPWD) measurements. The procedure has been utilized in several wells. The original well path of the first injector was planned to maintain a safe distance above an anticipated tar-bearing zone. Utilizing the new real-time viscosity evaluation, the well was steered closer to the tar zone several feet below the original plan, setting an improved well placement protocol for subsequent injectors. In the water- or lighter hydrocarbon-bearing zones, spectral analysis of NMR logs clearly accentuated micro- and macroporous carbonate intervals. The correlation between pore size and rock quality has been corroborated by FPWD mobility measurements. In one well, an extremely slow NMR relaxation may indicate wettability alteration in a macroporous interval. An integrated real-time evaluation of porosity, fluid saturation, hydrocarbon viscosity and pore size has enhanced well placement in a heterogeneous carbonate formation where tar barriers are also present. The approach increased well performance and substantially improved reservoir understanding.

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