bluuebunny/crossref_metadata_2025 huggingface dataset:
Research and Application of Nanometer Dispersion Oil Displacement Technology
Authors: Tian Miao , Xu Guorui , Wang Tao , Jia Yongkang , Feng Qing
Published: November 2020

With most oilfields at Bohai Bay enters into middle and late waterflood development stage, the oilfields have high water cut but low recovery degree. Chemical methods of enhanced oil recovery (CEOR) such as polymer are applied. However, the degradation and retention of polymer inside reservoir make it less attractive. Moreover, due to serious over-standard injected water quality or low-medium reservoir permeability, the CEOR are confronted with many challenges such as high injection pressure, difficulty in injection. Therefore, a new oil displacement technology of nanometer dispersion with good injectivity, dispersion stability and strong oil displacement characteristics is proposed. The focus of this study is to indentify the stimulation mechanism of nanometer dispersion and reveal its possibility for EOR in Bohai oilfield.

A set of experiments, including interfacial tension, contact angle, wettability, viscosity and core displacement, were conducted to investigate the effects of nanometer dispersion on the recovery of crude oil in Bohai Q oilfield. It was observed that nanometer dispersion fluid at the concentration of 0.5 wt.% can: 1) reduce the oil-water interfacial tension to 10−3 level; 2) decrease the oil-water contact angle from 55° to 9 °; 3) reduce the crude oil viscosity from 259 cp to 132.8 cp, with a viscosity reduction rate of 48.7%; 4) improve the oil washing efficiency of oil sand to as high as 79.1%; and 5) improve the oil recovery rate of core plugs by 25%∼46% compared with water flooding.

The lab-scale test was then extended to field-scale test. A pilot field test was conducted in Bohai Q oilfield, which was very successful, and obvious effect on controlling water and increasing oil production was obtaineded, with an oil increment of 6158m3. Laboratory and field test results show that the nanometer dispersion, as a new EOR technology, could considerably increase oil recovery and has a wide application prospect.
Monitoring Water Saturation Changes Using New Seismic Attribute in a 4D Seismic Study: An Example in Malaysian Field
Authors: Rezaei Shiba , Ghosh Deva Prasad , Babasafari Amir Abbas , Hermana Maman , Sambo Chico
Published: November 2020

4D seismic (time-lapse) is being used by oil and gas companies as a great tool for improving reservoir management. This technique is consist of repeated 3D seismic surveys captured at different times over same area. 4D seismic technology provides valuable information regarding spatial fluid movements which helps to overcome the challenges that the traditional surveillance methods are unable to solve and in addition it increases the ability of imaging fluid movement between wells after production and injection activities. This paper therefore focuses on 4D seismic method to estimate fluid saturation changes in a producing hydrocarbon reservoir after six years of production and water injection activities. The feasibility of new seismic attributes known as SQp and SQs (lithology and fluid indicator respectively) as a reservoir monitoring and management tool is analyzed and presented which shows the ability of SQp and SQs attributes to detect reservoir fluid saturation changes due to production and water injection activity in the field. To reach our objective, first deterministic seismic inversion was performed to extract seismic properties including Vp, Vs and Density for both base and monitor surveys. Base and monitor surveys were acquired in 1996 and 2006, respectively. Then the inversion results are being used to estimate SQp and SQs attributes volumes. In the final step estimated SQp and SQs attributes are used as an input in neural networks modelling for water saturation prediction. Based on the result of estimated water saturation and seismic attributes the fluid saturation changes was mapped, monitored and compared.
Advances Towards a Comprehensive Model of Laser-Rock Interaction
Authors: San Roman Alerigi Damian Pablo , Batarseh Sameeh Issa , Assiri Wisam
Published: November 2020

Laser applications provide unique advantages to applications in discovery, recovery, and production of hydrocarbons. A comprehensive numerical model would enable prediction, optimization, increase efficiency, enhance control, and further innovation. This work reviews the modeling methods, discusses key variables and physics, presents results, and introduces innovative solutions that make use of machine learning and artificial intelligence to solve an inherently multi-scale and multi-physics problem.

Two possible methods have been explored to model laser-rock interaction: mechanistic and statistical — the former uses as a set of coupled partial differential equations that adequately describe the physics involved. The statistical method uses advanced statistical analysis and supervised-learning to elucidate relations between the experimental settings and observations. The full-physics or mechanistic model was developed using finite-element and finite-difference methods; it incorporates coupled solvers for electromagnetic, thermodynamics, and geomechanics. The statistical model uses advanced statistical analysis and machine learning to characterize the dynamics and build a prediction algorithm.

A numerical model of laser-rock interaction must comprise physical dynamics that span over different time and spatial scales. When a laser beam impinges on a rock, a portion of the incident energy is absorbed as thermal energy, and a thermal gradient is created. The result is a distribution of physical and chemical changes such as spallation, melting, dissociation, calcination, or vaporization. The full-physical model can adequately capture the transient process; however, it requires a functional characterization of the dynamic rock properties, environmental conditions, and laser parameters. The statistical approach provides a prediction of the overall outcome of the process departing as a function of known input parameters, yet its precision depends on the availability of experimental data (outcomes and conditions). Key parameters are identified using statistical analysis. The modeling results agreed with experimental tests. Further, they evince that thermal properties and geomechanical stresses configuration have a significant impact on the process’ outcome. These methods can optimize and predict the interaction for multiple applications, ranging from heat treatment to stimulation.

Subsurface laser operations could provide the next generation of stimulation and workover tools for Oil and Gas. Numerical models of laser-rock interaction are essential to predict, optimize, adapt, and evaluate subsurface laser applications during development, test, and operation. This work provides a basis for the development of future numerical models and enables the next generation of subsurface photonic tools.
AutoEncoder Neural Network Application for Coherent Noise Attenuation in High Frequency Shallow Marine Seismic Data
Authors: Hamidi Rosita , Latif Abdul Halim , Lee Wei Yi
Published: November 2020

Conventional noise attenuation methods involve transforming noisy data into a filter domain where noise and signal can be separated. Deleting the noise components and transforming back the data into original domain, the filtered data is achieved. Coefficients representing the noise in the filter domain are selected by thresholding or manually which can result in a time-consuming process and also introduce error to what should be considered as noise energy. In this study, a model is developed using Deep Neural Network with AutoEncoder architecture to select the noise energy automatically in the Frequency-Wavenumber domain. The objective is to train a model that can attenuate coherent noise with certain isolated frequencies and varying amplitudes while preserving all reflections (weak and strong). The network is only trained on synthetic data; but its performance is evaluated on real high frequency marine data. The synthetic data have very simple structure of high frequency reflections contaminated with sinusoidal noise; outstanding performance of the proposed method on real data, however, shows the exceptional capability of the Deep Neural Network based filters.
End to End Real Time Data Cleansing, Standardisation and Reliability Towards a Smooth Digital Oil Field Deployment
Authors: Aissani Abdelmadjid , Tan Jun Yi Edwin , Thamilyanan Thivyashini
Published: November 2020

In order to remain competitive, digital solution in upstream oil and gas industry "is not one of the option, it's the only option". Nowadays, many companies have embarked on the digital transformation journey, and striving to become a data-driven organization. Service providers and consultancy companies constantly propose their latest technology such as Advanced Analytics, Big Data and digital oil field (DOF), however, the success of these digital solution relies heavily on data quality, where companies have always struggled to ensure a high level of data quality and make their readiness towards digital transformation questionable.

Real time data has become an essential tool in production surveillance, monitoring and asset optimization, it provides the engineers a breadth of view on the operational behavior of their wells and facilities. However, multiple issues arise that hinders the right data before flowing into the system such as instrument failure, bad data, wrong mapping, duplication, misleading descriptions and inconsistence in naming convention. These discrepancies will lead to low quality data being fed into the system and ultimately affect the efficiency of any deployed digital solution. Therefore, for any organization to leverage the value of their data and to unlock new opportunities the real time data needs to be well managed, governed and provided in high quality.

In this paper, the approach of real time data cleansing and standardization will be addressed in detail from end to end based on an initiative conducted in one of the signature field in Peninsular Malaysia. A thorough cleansing was done from the verification of instruments onsite, P&ID to all sub systems (servers) and end up with reporting all the finding (Completeness, Validity, Uniqueness, Consistency, Timeliness, Accuracy…). Therefore, provide a real time master data management, this helped in a good understanding of the real time data flow and identifying the responsible parties.

This has resulted in the development of a robust workflow accompanied by a clear RACI that can be used during the replication in other fields as well as future developments. Author believes that other operators may benefit from the proposed cleaning strategy and standardization logics to prepare for digital transformation.
Successful Application of an Integrated Fluid and Cake–Breaking System on Three Challenging Extended–Reach Wells Drilling Pinnacle Carbonate Reservoir
Authors: Correa Karen , Rincon Marco , Tieng-Soon Heu , Runtuwene Michael
Published: November 2020

A major operator in Malaysia planned to drill into a 6,000-ft horizontal thin-oil rim. The three-well campaign posed very challenging well deliveries for the operator due to potential losses to faults and karst zones, high uncertainty of reservoir productivity, long horizontal laterals, and openhole completions containing an Autonomous Inflow Control Device (AICD) with a low solids tolerance. An optimized drill-in fluid (DIF) and delayed filter-cake breaker were designed and tested to address the following challenges: reduced filtrate invasion, a targeted filter-cake breaking delay time, and high well production rates. In addition, there was a need for a mitigation strategy for total losses and the resulting impossibility of placing the delayed breaker across the entire reservoir section.

A customized NaCl-based 9.2 lb/gal DIF with an optimally sized ground marble bridging package was designed to facilitate filter-cake removal using a compatible delayed acid-release cake breaker. This was achieved through the addition of special additives in the DIF to increase the acid solubility of the filter cake. The DIF also included special additives proven to facilitate liftoff of filter cake at relatively low differential pressure, and for enhanced thermal stability of the polymers used.

Testing confirmed that the DIF filter cake was efficiently removed by the breaker within the customized delay time. Corrosion testing of the metallurgy used in the completion equipment demonstrated low corrosion rates at the expected 265°F bottomhole temperature (BHT) by both DIF and breaker systems.

Laboratory test results confirmed a high return permeability of 97.5% using the integrated DIF and breaker system. Three wells were drilled in the thin-oil rim reservoir and were completed using this system without losses. A relatively high ROP of 90 to 175 feet per hour without differential sticking issues maximized drilling efficiency and reduced the overall drilling costs. DIF density and properties were controlled through a dump-and-dilute technique. The wells were drilled to TD, and the completions run without incident. After the breaker was spotted, sufficient delay time was achieved with which to remove the wash pipe prior to closing the reservoir isolation valve. Approximately two months after spotting the first breaker, the wells were brought online, and the actual gas/oil production rates of the three wells were 50% above expectation.

This paper presents the design and successful application of an integrated DIF/breaker system for drilling and completing three of the most complex extended-reach wells drilled by the operator in Malaysia. The complementary designs of the DIF and breaker system components contributed to the successful drilling and production results of these three challenging wells.
Qualitative Root Cause Assessment Approach to Quantify the Impact of Flowline Internal Coating Disbondment
Authors: Lai Han-Lyn , Zakaria Mohd Hafiz , Ho Harry
Published: November 2020

Objective and Scope (25-74 words)

During High Speed Flushing (HSF) of two water injection flowlines (WIFL) located at offshore Sabah, Malaysia at water speed of 3.0m/s, internal Fusion Bonded Epoxy (FBE) coating flakes were observed being ejected from end of flowline by ROV. There were concerns that the dis-bonded FBE flakes would block the wells during operation causing a reduction in the water injection performance. The objective of this qualitative root cause analysis is to determine the likelihood of further internal FBE coating disbondment during operation and assess whether the water injection flowlines internal FBE coating failure is localize or systemic. Systemic failure is defined as the location of the internal FBE coating disbondment has no specific pattern and is randomly distributed throughout the entire flowlines. Localize failure is defined as the failure pattern is discernible and limited to a few specific linepipe along the flowlines.

Methods and procedures, process (75-100 words)

The qualitative roots cause assessment of the internal FBE coating disbondment consists of the following work streams:

Results, observations, conclusions (100-200 words)

In conclusion, there is no evidence to suggest that the FBE disbondment in the water injection flowlines was a systemic failure or that further application of flow would cause more coating to detach from the flowlines. It is deemed that the internal FBE disbondment is high likely localized based on the following observations:

New/novel information (25-75 words)

The water injection flowlines had started its operation since September 2015 and the wells performance is closely monitored by WRFM team. To date there is no decline in water injectivity being observed or reported for all water injection wells. Hence, the qualitative root cause analysis approach employed by the project team is deemed a workable analysis method in concluding the water injection flowlines internal FBE coating failure is localize and low likelihood of further disbondment during operation.
Practical Application of Machine Learning to Geotechnical Correlations
Authors: Tho Kee Kiat , Chan Nancy
Published: November 2020

Correlations are prevalent in the geotechnical engineering practice. This paper presents a practical machine learning approach for establishing improved geotechnical correlations. In the realm of machine learning, multiple input variables of significance can be readily and coherently incorporated into the model. This approach is illustrated in the context of correlation between undrained shear strength and the combination of depth, water content, liquid limit and plastic limit. The methodology is presented in a general form to facilitate adaptation to other geotechnical correlations.

The machine learning model is created in TensorFlow which is an open source machine learning platform. A dataset which consists of 1013 groups of undrained shear strength from undrained-unconsolidated triaxial test, depth of sample, water content, liquid limit and plastic limit data are compiled. 70 % of the randomised dataset are used for training and validating the model while the remaining 30 % are used to test the performance of the model. The machine learning model consists of an artificial neural network model with one input layer, four hidden layers and one output layer. The training takes several minutes on a laptop equipped with a Graphics Processing Unit.

The classical approach would have been to correlate the undrained shear strength to liquidity index which is a combined parameter computed from water content, liquid limit and plastic limit. By comparing the predictions of the machine learning model on the test dataset against those computed based on dataset-specific correlation between undrained shear strength and liquidity index, it is evident that a significantly improved correlation is obtained using the machine learning approach.

Due to the intricacy of multi-dimensional regression analysis, classical geotechnical correlations are typically determined by method of curve-fitting with just a single independent variable. Soil, by nature, is a complex material that is characterised by multiple index properties. Therefore, it is intuitive that geotechnical correlations can be improved by incorporating multiple classification properties or measurements. The machine learning approach described in this paper, which is implemented using an open source platform and readily accessible to industry practitioners, alleviates the legacy limitation of a single independent variable leading to improved geotechnical correlations. More importantly, this machine learning approach fits in perfectly with the digitalisation initiative increasing embraced by the oil and gas industry to improve on safety, efficiency and profitability.
Breakthrough in Scale Inhibitor Chemical Selection through Digital Application
Authors: Collins Jonathan Anthony , Dunsmore Braden , Grutters Mark , Howard Lee , Shintre Nitin , Selvam Kathiravan
Published: November 2020

Production chemicals are essential to the operation of oil and gas production systems – but chemicals such as scale inhibitors are complex, with different chemistries providing protection for different types of situations, depending on system conditions. To date, the standard industry process has depended on experience, laboratory testing and field trials.

We are introducing a first of-its kind method of scale inhibitor selection which takes advantage of digital capabilities, rich performance data and our deep chemicals expertise to eliminate much – and sometimes all – of the laboratory work.

In specific, this process eliminates the time needed for short-listing and testing scale inhibitor chemistries in the laboratory. We have instead applied digital analytics to our extensive historical data library, making it possible to recommend the appropriate chemistry with reduced – or even completely without – laboratory testing. Comparing system conditions to historical laboratory data, we can generate relevance factors that relate to the conditions of the system of interest. If sufficient information is available in the database, the analytics can also predict the results that would be expected in a given laboratory test. In addition, data on where each scale inhibitor has been applied is stored in the database, giving a link to field scenarios and case histories, thereby correlating laboratory and field performance.

Laboratory tests confirm that the use of this new digital application results in much quicker (same day) and more accurate product recommendations, with statistical qualification. It allows the user to generate faster recommendations, optimize dosages, generate tailored products, and avoid delays from shipping samples around the world. Ultimately, it provides more statistically relevant information on which to base field decisions, minimizing risk for the operator, as well as much quicker and optimal product recommendations.

We believe that this revolutionary scale inhibitor chemical selection tool is the first of its kind to incorporate such an extensive database of historical test data with digital correlation to existing field use information. We believe it is the future for designing the optimum scale treatment program for oil and gas fields.
Unconventional Mud Design to Address Narrow Pressure Window and High Overbalance HPHT Offshore Well
Authors: Razak M. Solehuddin , Devadass Lingges
Published: November 2020

Alpha 1 was recognized as the highest overbalanced well drilled in operator's history. A comprehensively designed superior mud system has enabled the well to be drilled successfully, meeting its objectives of producing shallow and intermediate intervals and able to appraise deeper 8-1/2" HPHT section. The HPHT section exhibits a marked pressure spike to pore pressure up to about 14,000psi with 310°F bottom hole temperature. The formation prognoses are very much uncertain due to limited data available from offsets. This considerable HPHT drilling challenges are further compounded by the high overbalance pressure - approximately 6,800psi observed while drilling with 18.4ppg mud weight.

Drilling mud designed for high overbalanced pressure well requires special attention particularly on the HPHT filtration control and mud rheology. In deeper section where wellbore pressure control is critical with approximately 1.5ppg drilling margin, the mud formulation and rheology was optimized in minimizing ECD. The components of the mud were heavily scrutinized to minimize risk of wellbore losses and differential sticking. Low fluid invasion system was introduced to provide wellbore shielding mechanics. Operator has made initiatives of conducting unconventional laboratory works in assuring the technical performance. Cost reduction initiative was also made by optimizing mud design with surplus mud and chemical inventory. These were incorporated into the mud design as to have low cost and fit for purpose mud formulation.

In actual operation, the mud rheology and ECD were deviated from the plan. Both major deviations demanded several adjustments on the mud formulation. Several lab tests were conducted and unconventional mud apparatus were brought offshore for further fine tuning on mud formulation. The 8-1/2" HPHT hole section was successfully drilled with no issue pertaining to losses, drag during tripping and differential sticking. The best practices and lessons learnt replicated from few HPHT wells drilled previously, in combination with the close collaboration on laboratory works with contractors has contributed greatly to the success of the well.
Offshore Wind Energy in Asia: Technical Challenges and Opportunities
Authors: Lau Hon Chung
Published: November 2020

Studies show that coastal regions of the East China Sea, Japan Sea, Philippine Sea and parts of the South China Sea have adequate wind speeds for offshore wind energy while coastal regions in equatorial Asia do not. Inexperience in installation, operation and maintenance (O&M) and the high levelized cost of electricity (LCOE) are major challenges in Asia’s roadmap to implement offshore wind farms. Several technologies in wind turbine design that will aid implementing offshore wind farms in Asia have been identified. They are weight reduction, increased reliability to reduce O&M, typhoon resistant design, integrating substructure into wind turbine design, electrifying oil and gas platforms by wind turbines, and combining multiple renewable energy systems in a single floating platform.
An ANN-Based Model to Artificially Transform a Floating Vessel into a Wave Monitoring Buoy
Authors: Sidarta Djoni Eka , Tcherniguin Nicolas , Tan Jaime HuiChoo , Teng YihJeng
Published: November 2020

Floating platform offshore operations, such as load transfer from a supply boat and hydrocarbon offloading operations, are often limited by sea conditions. Access to sea condition information from a nearby wave/environmental monitoring buoy is not always available or there may be delays in data transmission. In the absence of reliable and accurate data from a nearby wave buoy, the motions of a floating platform/vessel may be used to estimate the sea conditions.

This paper presents a method in using Artificial Neural Network (ANN) models to map the motions of a floating vessel to the wave elevations and to eventually estimate the significant wave heights of the sea the floating vessel is in. The ANN models can be trained using either: (1) measured data in the form of measured vessel motions and data from a nearby wave buoy, or (2) simulated data, i.e. vessel motions computed using numerical simulations. In this paper, demonstration of the ANN method uses simulated data under various sea conditions.

The trained ANN models are tested for sea conditions that are not part of the training data, and the ANN predictions are found to be very close to the results calculated using numerical simulations. This is an important step to show that the trained ANN models have learned the presented information and can generalize the knowledge. The methodology presented in this paper may be used to establish an ANN model for estimation of the significant wave heights based on the measured motions of a floating vessel.
Avoidance of Leak/Rupture through Implementation of Digital Integrated Pipeline Integrity Assurance System i-PIMS
Authors: Mat Tuselim Ahmad Sirwan , Mohd Ali Napiah Mohd Nazmi , Abu Bakar Mohd Hisham
Published: November 2020

In PETRONAS, there are on-going initiatives at petrochemical plants, gas processing plants, Upstream's well engineering and retail business in pursuing the digitilisation in line with the Industrial Revolution (IR) 4. The aim of the initiatives is basically to improve the efficiency of critical processes thus at the end will reduce overall cost and improve production margin and revenue/profitability.

This paper will present the initiative of PETRONAS' Pipeline fraternity consisting of pipeline experts, managers and engineers in the development of intelligent and integrated pipeline integrity management system. The system is designed to have minimal people intervention as data will be automatically uploaded by Inspection & Maintenance (I & M) vendors and field technicians through interface software and utilising artificial intelligence/ machine learning for descriptive, predictive and prescriptive analytics. It is envisaged that by having the system, critical decision-making pertaining to integrity, safety and reliability of pipeline system could be done in ‘split seconds’ extending the asset's life and eliminating unwanted incidents i.e. leak/rupture.

Furthermore, standardisation of pipeline risk and integrity software/tools among Operating PETRONAS Units (OPU)/regions will provide cost savings in the long term compared to current practice of having off-the-shelf software/tools. Integration of relevant corporate software/tools and the intended software/ tools will further provide cost savings in terms of database management and enhanced efficiency.

There are few other initiatives running in parallel with the i-PIMS i.e. using advanced acoustic emission technology to detect corrosion anomalies using new developed sensors and also establishing algorithms/analytics for corrosion's growth, location and position throughout pipeline length; formation of dynamic free spanning for offshore pipeline; and predicting/monitoring 3rd party impact occurrence.

Development of pipeline predictive analytics is to gain significant improvement in PIMS for better integrity status verification, faster decision making and optimization for I&M activities. The overall outcome/results/algorithms will be integrated into i-PIMS as part of final assessment.

It is PETRONAS' aspiration that eventually, descriptive analytic of i-PIMS i.e. critical pipeline integrity performance indicators and critical processes can eventually able to be accessed via mobile apps which will be a ‘pace-setter’ in overall pipeline integrity management scheme i.e. ‘effectively managing pipeline at fingertips’.
The Effect of Mercury to Carbon Steel in CO2 and H2S Environment
Authors: Jaafar Rohana , Mohammed Nor Azmi , M Surday Amir Sharifudin , Ahmad Rusli Ahmad Mustaza , Rikan Noor Laila , Md Aris Noraina Suyanti , Suhor M. Firdaus , Abas Ahmad Zaki , Hasan M. Hawari
Published: November 2020

Objectives/Scope

This paper is about a study on the impact(s) of elemental and ionic mercury (Hg) to carbon steel corrosion in sweet and sour environments with and without Corrosion Inhibitor(CI) injection.

Methods, Procedures, Process

Evaluation on the effect of Hg deposition and the corrosion behavior via Corrosion rate using Linear Polarization Resistance (LPR), solution properties, surface profile and corrosion product analysis are performed. Low pressure bubble test and autoclaves test are conducted under multiple variables to study the corrosion rate behavior. Fluid Analysis is performed using ICP-OES and XRD to analyse the chemical reaction of the fluid. Surface analysis is conducted using Visual inspection and XRF.

Results, Observations, Conclusions

The bubble test analysis shows that elemental and ionic Hg does not affect the corrosion rates under CO2 environment. Likewise, in H2S-containing environment, elemental Hg do not effect H2S corrosion evidence by the low pre-corroding corrosion rate. However, ionic Hg is observed to influence H2S corrosion where higher corrosion rate is measured. This is potentially due to the reaction between ionic Hg and H2S lead to the formation of HgS, depriving carbon steel inhibitive effect by H2S. The addition of Corrosion Inhibitors is observed does not reduce the corrosion rate probably due to the reaction between the ionic Hg and the sulphide element from the CI resulted into decreasing of filming tendency. HPRCE Autoclave result shows that CI had successfully reduce the corrosion rate to the targeted corrosion rate provided higher CI injection dosing is introduced.Significant HgS spectrum observed during XRD analysis reflecting ionic Hg mighthave reacted with H2S and CI. This supported that the presence of ionic Hg might have interfered the inhibitive mechanism of the CI and delayed the formation of passive layer on the metal. ICP-OES and XRF indicated Hg traces potentially due to high reaction rate between ionic Hg and injected CI thus accelerated the formation of HgS.

Novel/Additive Information

CI formulation without any sulphide composition should be used if ionic Hg is present in order to ensure the CI effectiveness and it consumption during operation. In the event where the CI formulation cannot be changed, an enhanced pre-qualification evaluation as conducted in this study is to be carried out if ionic Hg is detected in the system to ensure the CI is effective and compatible to be injected.
Numerical Well Testing Interpretation Method and Application Under Interference from Adjacent Well in Polymer Flooding Reservoir
Authors: Kang Xiaodong , Zeng Yang , Zhang Jian , Tang Engao , Cheng Shiqing
Published: November 2020

The offshore polymer flooding reservoirs are mostly in the middle and late stages of oilfield development, and there are multi-well systems. At present, most of the well testing methods for polymer flooding reservoirs are based on single well system, which leads to the fact that the actual data fitting effect is not ideal. By considering the influence of adjacent production well or polymer injection well and the physical and chemical effects of polymer solution such as shear, diffusion and convection, the well test interpretation method of polymer injection well considering adjacent well interference is established, type curves were plotted and its influencing factors were discussed by the numerical inversion method. The result showed that the type curves have five regimes, the pressure derivative curves show obvious upward warping under interference from production well, while the pressure derivative curves first decrease and then continue to rise under interference from polymer injection wells. Polymer injection well test curves show obvious non-Newtonian fluid characteristics when considering adjacent well interference, and can not be analyzed by conventional adjacent well interference test method. The example application proves the correctness and reliability of this method, which provides a theoretical basis for dynamic adjustment of polymer flooding reservoir.
Customer and Design Engineer Interaction Process Enhances Drilling Efficiency for the Operator in Offshore Malaysia
Authors: Mohamed Sabri , Che Ismail Mohd Hauzi , Nordin Mohd Haikal , Mohd Affandi Abd Razak , Mohd Zurhan Mohd Syahmi
Published: November 2020

In general, the formation in offshore East Malaysia is more challenging than the formation in offshore West Malaysia. One reason is primarily because of the highly interbedded soft and hard formation throughout the well. What is even more challenging is the nature of polycrystalline diamond compact (PDC) cutters, which are prone to breakingbecause of the impact from those highly interbedded formations.

Field T is a fieldwithin the area that is well known for using a significant amount of drill bits to drill a well. Most PDC bits exhibited bad dulls and cutting structure conditions, particularly in the shoulder area. Broken and chipped cutters have resulted in the bits being pulled out of hole prematurely, unable to continue drilling to well total depth (TD). In the early days during the exploration phase, the PDC bits used in this field ended up mostly with ring out (RO) dulls regardless of the number of blades being used.

This bad dull condition improved significantly during Phase 1A development drilling in Field T compared to drilling during exploration. However, it has being recognized that further improvements could still be made during Phase 1B development drilling in terms of rate of penetration (ROP) without compromising bit durability.

To address the challenge, the approach should be a different bit design modifications rather than just a taking an off-the-shelf bit.Collaboration between the drilling project team and drill bit design engineers began months before the project was scheduled to start. This began the continuous interaction process between both parties to enhance drilling efficiency for the operator.

After several meetings, discussions and presentations, the drilling project team and drill bit design engineers developed the optimum bit design solution for this application. Several design iterations were performed to obtain the most efficient cutting structure layout before finalizing and manufacturing the bit specifically designed for this field T.

As a result, the entire 8.5 inch section was drilled using one specifically designed bit with an outstanding rate of penetration improvement, which was the objective of the 8.5 inch holesection. The successful result reflects a great team effort attained by thorough planning and execution process by both drilling project team and drill bit design engineers.
Geohazard-Seismic: Gas Cloud Characterization Through Seismic Attributes
Authors: Hasni Norazif Anuar , Shahman Nur Shafiqah , Talib Jasmi Ab , Ghosh Deva Prasad
Published: November 2020

In general, offshore geohazards consist of variety in geological features that contribute potential risks to human health, safety and the environment due to consequences of long or short period of geological processes. A geohazard can be defined as a geological state that may lead to widespread damage or risk. Geohazards are geological and environmental factors and involve long-term or short- term geological processes. Geohazards may have relatively small features, but they can also spread out to huge dimension so as to affect local and regional socio-economy to a large extent (Wikipedia, 2019). From the viewpoint of the oil and gas industry, geohazards mean either geological processes or factors to cause such processes that may provoke damage to the industry to risk human health, safety and the environment no matter where they are caused. Geohazards could also risk the suspension of the oil and gas production for a certain period of time. There are many type of geohazards related to offshore oil and gas developments such as "mud diapirs and volcanoes", "fault ruptures", "shallow gas", "seabed gas hydrates", "debris flow run out", "unstable slopes", "landslides", "pockmarks", "liquefaction", "turbidity current and rock outcrops" and "Methane-Derived Authigenic Carbonate (MDAC)". The geohazards can occur in the form of combination between various types of geohazards. It may cause huge damage and complicated problem to be solved. Each geohazards type has different problems solving due to different period of occurrence in geological processes. Generally, this paper will explain about the identification of gas cloud by applying several seismic attributes on specific parameter.
A Systematic Approach to Deploy a Novel Nondamaging Fracturing Fluid to Field
Authors: Karadkar Prasad , Alabdrabalnabi Mohammed , Liang Feng , Buenrostro Adrian
Published: November 2020

Guar gum and its derivatives based fracturing fluids are most commonly used in hydraulic fracturing. For high temperature wells, guar-based fracturing fluids need to be formulated with higher polymer loading and at a high pH that leaves insoluble residue and tendency to form scales with divalent ions. In this paper, a systematic approach to field deploy a novel low-polymer loading, nondamaging acrylamide basedfracturing fluid system is presented.

Thermally stable acrylamide-based polymer with reduced polymer loading of 30-40% less than guar-based fracturing fluid was considered to minimize formation damage concerns. For successful field deployment, a novel nondamaging fracturing fluid was evaluated in following sequence: chemical management and quality control, optimization of fracturing fluid formulations with field water, field mixing procedure, onsite QA/QC, friction analysis, leakoff analysis, data frac analysis and execution of main fracturing treatment. In both scenarios, batch mixing and on-the-fly mixing of linear gel were evaluated. The friction of crosslinked fluid was analyzed by using bottomhole gauge and fluid efficiency was evaluated during data frac analysis.

This paper presents rheological studies at bottomhole static temperature (BHST) and cool down temperatures of selected well candidates that demonstrate superior thermal stability of this novel fracturing fluid. With polymer loading of 25 lb/1000 gal, the fluid viscosity stayed above 300 cP at 100 1/s shear rate for 2 hours at 290°F. The fracturing fluid formulations were optimized using both live and encapsulated breakers with high pressure and high temperature (HPHT) rheometer. Due to the fast hydration of the base polymer, the linear gel was mixed both in batches and on-the-flying during the main fracturing treatment. Slightly higher friction at higher pumping rate was observed by the down hole gauge during data frac for this novel fracturing fluid as compared to guar-based fracturing fluid. The main fracturing treatment was successfully executed with 45-50 barrels per minute (bbl/min) pumping rate with increased proppant concentration up to 5 pounds per gallon (ppa) using 30/50 high strength proppant (HSP) proppant.

The fracturing fluid system based on the novel acrylamide copolymer offers advantages over guar-based fracturing fluid such as low polymer loading, excellent high temperature stability and less formation damage. This paper presents a systematic approach and lesson learnt during novel fracturing fluid deployment.
A Case Study on the Largest Exploration Survey in Asia: Unlocking the Hydrocarbon Potential of Frontier Areas, Offshore Sabah, Malaysia
Authors: Chakraborty Rupam , Tham Michelle , Sazykin Artem , Menzel-Jones Gavin , Miller Paul , Tu Ching , Barlass David , Adelman Natalie
Published: November 2020

Deep-water (1000 m+) Sabah, Malaysia, is a frontier exploration province proximal to successful exploration trends within the Sabah thrusts zone and Luconia carbonate shelf. The basin is on trend with numerous proven petroleum systems; however, it remains underexplored with minimal drilling activities targeting the deep-water hydrocarbon plays. The need to build reliable regional interpretation over large prospective areas led to a broadband multimeasurement towed-streamer acquisition over 19,500 km2 in offshore Sabah. In this work, we illustrate an integrated workflow that incorporates contemporary broadband processing, interpretation-guided earth model building, and multiphysics input to interpretation to generate a high-resolution seismic image that will accelerate exploration in the region.
Experimental Study on Enhanced Shale Gas Recovery by Competitive Adsorption of CO2-CH4 Under High-Temperature, High-Pressure Conditions
Authors: Wang Jinjie , Ng Qi Hua , Lau Hon Chung , Stubbs Ludger Paul
Published: November 2020

Experiments were carried out to study the effectiveness of CO2 injection to enhance the recovery of CH4 in a shale core sample. Two types of experiments were performed. The first was the adsorption isotherm of CH4 on the core at 30°C. The second was a series of coreflooding experiments where the core was initially saturated with CH4 at 30°C and 100 bar. CH4 recovery by depressurization to 80 bar and that by N2 or CO2 injection to 140 bar followed by depressurization to 80 bar were compared. Results showed that depressurization alone gave a recovery factor of 27%. However, N2 injection followed by depressurization gave an additional 17% in CH4 recovery due to reduction in partial pressure of CH4 during depressurization. CO2 injection followed by depressurization gave a further 4% in CH4 recovery compared to N2 injection followed by depressurization due to competitive adsorption of CO2-CH4. However, the CH4 recovery due to competitive adsorption would have been significantly higher had the dead volume in the apparatus been eliminated. Our experiments suggest that CO2 injection followed by depressurization may be an effective enhanced gas recovery method for shale reservoirs due to the combined effect of partial pressure reduction and competitive adsorption. Therefore, more research in this area is warranted.
Application of Thixotropic Cement Slurry to Cure Losses in Depleted Zones in Coal Seam Gas Wells
Authors: Zaman Mohammad , Shaban Alex , Iyer Venkat , Wuthayavanich Ekkalak , Saunders Troy
Published: November 2020

Complete to intermittent dynamic losses during drilling operations in the Early Permian reservoirs of the Bowen Basin are common because of depleted zones, particularly in the Bandana Coal Measures. The losses encountered while attempting to drill to total depth (TD) result in notable setbacks in time, remediation costs, and zonal isolation integrity. Operators have access to a large portfolio of loss circulation (LC) treatments depending on the loss type, rate, and nature of losses. This paper presents a low-solids, highly thixotropic (LSHT) cement system that can help cure losses without incurring costly nonproductive time (NPT).

During the recent Springwater campaign, which consisted of 12 wells targeting the Cattle Creek Coal Measures, three of the wells experienced significant to total losses. A number of conventional lost circulation materials (LCMs), including particulate materials, reticulated foams, and fibers, were unsuccessful in curing the losses. As an alternative to a conventional LC cement plug, an LSHT cement system was deployed.

The low-solids content and avoidance of any traditional LCMsenable the LSHT system to be pumped through the bottomhole assembly (BHA), which allows for continued drilling. The LSHT cement system is shear-rate dependent, yielding to thin rheologies on application of shear to easily penetrate into the loss zone. When shear is reduced, the slurry gels rapidly to arrest the rate of flow. Additionally, the quick early compressive strength development at shallow depths allows operations to continue without incurring significant loss of operating hours. The solutions provided were pumped through open-ended pipe in one case and through the BHA with a drilling bit in another; both performed in the same manner without hampering equipment capability.

Successful application of the LSHT cement technology helps minimize time lost using conventional cement plugs because the LSHT cement can be pumped through the BHA, saving time associated with tripping in and out of the hole to change the BHA. Additionally, the system's early compressive strength development yields time savings, along with savings in otherwise lost fluids, and achieves drilling efficiencies to help manage drilling operations costs.
Offshore Renewable Power to Hydrogen Provides a New Technical Solution for the Utilization of Offshore CO2-Rich Natural Gas
Authors: Song Pengfei , Shan Tongwen , Hou Jianguo , Chang Le , Li Youwu , Wang Xiulin
Published: November 2020

China now is the largest natural gas importer in the world, with the dependency on foreign countries has reached to 45.3%.On the other hand, China has a huge amount of natural gas resources in the South China Sea to be developed, but most of them are CO2-rich gas which contains 15%~80% CO2 located in the deep sea. How to develop these valuable offshore gas resources economically, efficiently, sustainably and environmental friendly, without causing greenhouse gas emission, has always been one of the biggest challenges in the offshore petroleum industry.

Power-to-Hydrogen (PTH) from offshore renewables and CO2 methanation are expected to provide a new technical solution for the utilization of offshore CO2-rich gas. This method can improve the composition of CH4 to meet the requirements of economic pipeline transportation, and even the requirements of liquefaction to LNG.

However, this technology is still under development. Regardless of the technology itself, the bottleneck exists in the balance between the costs of hydrogen and natural gas production and the economy condition for the whole life cycle of gas field development. But this technology still has the potential to provide a new solution for the development of CO2-rich natural gas resources. It is preliminary estimated that when the costs of offshore power are less than ¥0.3 / kWh, the project can be commercialized.
Big Data and Machine Learning: Effective Tools for Ensuring Well Integrity
Authors: Savini Marcus Blane , Domec Brennan Scott
Published: November 2020

The application of big data analytics, artificial intelligence, and machine learning to solving challenging problems is ever-increasing in the oil and gas industry. These techniques have already been proven to be powerful tools that can not only improve safety and reliability but can also provide more consistent and accurate decision-making capabilities as compared to conventional methods. This paper will detail a real-world application of big data analytics and machine learning to the tubular connection make-up process, realizing significant benefits over traditional human-evaluated methods. While the focus of the paper will be on a single application, similar approaches may be beneficial to other applications and other industries, achieving similar benefits.