bluuebunny/crossref_metadata_2025 huggingface dataset:
De-Risking the Prospect Maturation by Hydrocarbon Saturation Assessment on Carbonate Reservoir Characterisation, Central Luconia, Sarawak, Malaysia
Authors: Ahmad Tarmizi Nor Aiman , Lim Pei Wen , Ou Kuan Ee , Tolioe William Amelio , Hanalim Linda
Published: November 2020

Several discoveries of carbonate reservoirs are reported in Central Luconia, which initiated numerous carbonate characterization studies there. The outcomes are vital as analogues for prospects maturation, especially in estimating input parameters for hydrocarbon volume in-place assessment. However, hydrocarbon saturation is hardly discussed. This paper presents a comparison of some saturation-height functions commonly used in the oil and gas industry leveraged as the regional approach preference to optimize hydrocarbon saturation assessment in the volumetric estimation of carbonate reservoir in Central Luconia.

This study focuses on hydrocarbon saturation, one of the key parameters in the volumetric assessment. A few saturation height function methods are tested on the studied field, integrated with the understanding of carbonate characteristics like rock quality and rock type on analogue field or block, to optimize the prospect assessment. Standard and advanced log data were used in this context, to effectively derive saturation height functions. In addition, capillary pressure (Pc) data was used to calibrate the derived saturation height function equation. The saturations from different methods are then plugged-in for volumetric estimations.

One of the two outcomes from this study is a thorough comparison analysis of saturation values obtained via different methods; and a suitable analogue to be applied for future prospect evaluations as regional model, obtained through analyzing end results of volume in-place calculated by various saturations computed, coupled with in-depth geological understanding of the prospects to analogue field or block. The saturation height function was weighted by area-depth to account for the gross rock volume and compared against post-drill results. The analogue is to be utilized to derive saturation height equation when there is no data available for any prospect.

To-date, there is a rising interest in carbonate reservoirs prospects evaluations, which usually come with very limited data. It is hard to ascertain the techno-commerciality, to risks with such minimal information, from volume in-place to economics. Hence, the findings of this study will assist in reducing the uncertainty in hydrocarbon saturation assessment. The analogue developed is handy to be replicated for similar carbonate reservoirs in Central Luconia, or other locations. By selecting the appropriate saturation assessment methodology and suitable analogue as a reference, the risk and uncertainty of prospect evaluation and maturation shall be further diminished.
Thermal and Rheological Investigations on N,N'-Methylenebis Acrylamide Cross-Linked Polyacrylamide Nanocomposite Hydrogels for Water Shutoff Applications
Authors: Keishnan Mohan Raj , Michael Feven Mattewe , Almohsin Ayman Mohammed , Alsharaeh Edreese H
Published: November 2020

Herein, we report thermal and rheological investigations on PAM nanocomposite hydrogels that are cross-linked with N,N’ methylenebis acrylamide (MBA) in presence of Zr(OH)4 and Zr(OH)4G fillers with a potential for water shutoff applications. The fillers such as Zr(OH)2 or their composites Zr(OH)4G were found to enhance the thermal and mechanical characteristics of the PAM hydrogels in addition to the organic cross-linker. The samples were prepared with different weight percentages of MBA with and without the presence of fillers. The samples were characterized by dynamic scanning calorimetry (DSC), thermogravimetric analyses (TGA) and dynamic mechanical analyses (DMA). Upon investigating the thermal properties of the hydrogels, the neat-PAM hydrogels have shown a maximum of the bound water content of 0.45 with 0.3 wt% of MBA while the PAM-Zr(OH)4 with 0.3 wt% of MBA cross-linker had higher bound water of 0.41. However, when Zr(OH)4G was used as a filler, the ones with 0.15 wt% of MBA showed a higher bound water content of 0.35. The TGA results revealed that there is a significant increase in the degradation temperature (Tg = 181°C) for the neat-PAM hydrogel with 0.3 wt% of MBA in comparison to that of neat-PAM with 0.15 wt% of MBA (175°C), indicating that the chain mobility of the polymer matrix at a lower temperature was decreased when the cross-linker concentration was increased. For the PAM-Zr(OH)4 and PAM-Zr(OH)4G nanocomposites, the Tg were found to be higher with 0.3 wt% of MBA in comparison to the ones with 0.15 and 0.6 wt%. The gel strength for neat-PAM is calculated to be 13.5 and that of PAM-Zr(OH)4 and PAM-Zr(OH)4G nanocomposite hydrogels are 4.2 and 12.8 respectively. In contrast to the gel strength, the PAM-Zr(OH)4 nanocomposite hydrogel displayed a high damping factor (tan δ = 0.23) in comparison to that of PAM-Zr(OH)4G (0.08) and neat-PAM (0.07).
Condensate Banking Characterization and Quantification of Improvement from Different Mitigations Using Pressure Transient Analysis: A Case Study in Hai Thach Field Offshore Vietnam
Authors: Pham Duy Hoang , Hoang Son Ky , Trinh Vinh Xuan , Tran Tung Vu
Published: November 2020

To successfully mitigate a near-wellbore condensate blockage, the status of the condensate blockage must be thoroughly understood. This case study proposes a new technique of pressure transient analysis (PTA) to investigate the formation and impact of condensate banking on well deliverability. This new PTA technique was successfully applied to the largest reservoir of the high-pressure high-temperature Hai Thach field, providing valuable information in designing mitigation programs. Finally, two mitigation methods (hydraulic fracturing and condensate bank removal) were investigated to evaluate their potential production enhancement.

The entire production history with many buildups was matched systematically and simultaneously by PTA to determine the skin factor evolution in addition to reservoir permeability. An increasing trend of skin factor confirmed the presence of condensate blockage in the near-wellbore area and provided information about the time required for the condensate bank to form. In addition, the size of the condensate blockage was obtained from the radius of the radial composite reservoir model. Finally, improvement on production rate by two mitigation methods was examined using typical skin factors achieved by these methods.

Two production wells from the main reservoir of Hai Thach field were selected for this study. From observed data, the gas rate of the first well reduced rapidly from 10 MMSCF/d to 4 MMSCF/d and the second well had a low stable rate of 3 MMSCF/d. The application of PTA revealed that skin factor of the first well dramatically increased from 0 to roughly 11 and similar behavior was also captured at the second well as this value increased from 0.5 to around 5. This upward trend of skin factor confirmed the presence of condensate blockage at near-wellbore regions of these wells and it took approximately 5 months to form the condensate bank. The radius of condensate bank was also determined at roughly 14 ft and the average permeability of these wells fall in the range of 0.2 to 0.5 mD. In addition, the mitigation analysis on two production wells showed that hydraulic fracturing and condensate bank removal methods could improve well production rate up to approximately 180% and 100%, respectively.

From conventional well testing techniques, it is challenging to obtain further information of condensate bank in a near-wellbore region. This case study proposes a novel application of PTA which successfully provided in-depth knowledge of condensate blockage, such as condensate bank size and formation time. This information is crucial in designing mitigation programs to improve recovery of affected wells. The potential enhancement on production rate from different condensate banking mitigation methods was also quantified, providing valuable information on the feasibility of such mitigation jobs.
Production of Biopolymer Schizophyllan Using Local Sources in Malaysia
Authors: Gunaji Radhika Gautam , Junin Radzuan , Bandyopadhyay Sulalit , Guttula Pavan
Published: November 2020

In recent years polymer flooding has been field tested extensively and has succeeded in many Enhanced Oil Recovery (EOR) projects. The use of synthetic polymers in EOR is undesirable from an environmental perspective. Further, due to limitations of the existing synthetic polymers in high temperature and high salinity conditions, thermal degradation among other drawbacks, biopolymers have attracted the attention of the petroleum Industry. Recently, the use of biopolymer schizophyllan for polymer flooding operations has been found to have advantages such as stability under high temperature and high salinity conditions. This biopolymer is commercially produced from the fungus schizophyllum commune using glucose as a carbon source via fermentation process and is currently available in small quantities as an expensive purified pharmaceutical and cosmetic grade material. Our study aims to utilize locally available sources in Malaysia to synthesize the above biopolymer making it cost effective. The fungus schizophyllum commune commonly known as "cendawan kukur" in Malaysia was used as a starting material. Different production media containing carbon and nitrogen sources, required for the growth of the fungus, were utilized for the biopolymer production. Initial viscosity studies carried out using rheometer showed that, the production media comprising sago starch as the carbon source and potato extract as the nitrogen source, showed the highest viscosity value of 0.12 Pa-s at 30°C. Therefore, this media was chosen as the most favorable media for the biopolymer production. Further, the biopolymer extracted from this media was identified by Fourier Transform Infrared (FTIR) spectroscopy which showed similarity in chemical structure with reference to commercial schizophyllan data from the literature. The results from Thermo Gravimetric (TG) analysis showed that the biopolymer was thermally stable at higher temperatures similar to that of the commercial schizophyllan. This study would develop the utilization of locally available sources to produce schizophyllan for polymer flooding operations by explaining various characteristics so as to meet the expected requirements for it to be applied in an oil field.
Deep and Thin Overpressure Reservoir Characterization of Paleogene Formation Wenchang in the Enping 17 Sag of the South China Sea
Authors: Liu Jun , Li Yingwei , Liang Donghai , Peng Guangrong , Bai Haijun , Ruan Xiaomin , Xu Jianhua , Zeng Rui
Published: November 2020

Only one wildcat well had been drilled for deep formation hydrocarbon exploration (4400 m to 4800 m) and partially penetrated into Lower Paleogene Formation Wenchang (FM WC) without commercial oil discovery in the Enping 17 Sag, northern of the Pearl River Mouth Basin in the South China Sea. Although large thicknesses of grey lacustrine mudstone with abundant organic material are proven to be the regional source rock, lack of a good reservoir for hydrocarbon accumulation in FM WC is the failure reason for this well. Encountering a 9-m-thick sand layer at a depth of 4650 m indicates that braided fluvial delta and lowstand turbidite sandstone may develop in the FM WC, and the zones below upper section 1 of FM WC are proved to be overpressure. It protects pores in the deep reservoir from compaction. Condensate gas was observed by drill stem test (DST) in overpressure sand layer while no gas was measured in sand layers above the overpressure zone. Aiming at delineating effective reservoir in FM WC, an integrated workflow for 3D seismic reservoir characterization of offshore deep and thin layers was developed for this area without sufficient well data. The workflow includes seismic data reprocessing, well log-based rock physics analysis, seismic structure interpretation, 3D simultaneous amplitude variation with offset (AVO) inversion, 3D lithology prediction, and geological integrated analysis. We present four key solutions to address four specific challenges in this case study: 1) application of adaptive deghosting (AD) techniques to remove the source and streamer depth-related ghost notches in the seismic data spectrum and the bandwidth extension (BWXT) technique to improve the seismic data resolution; 2) a practical rock physics modeling approach to consider the formation overpressure for pseudo-shear sonic log prediction; 3) interactive and synchronized workflow between prestack 3D AVO inversion and seismic processing to predict a 9-m-thick layer in FM WC after 60+ rounds of cyclic tests; 4) cross validation between seismic qualitative attributes and quantitative inversion results to verify the lithology prediction result with limited well data.
Selection of Right Inspection Tool for Challenging Pipeline
Authors: Abdullah Mohamed Ali , Koi Swee Ling , Rahmad Ahmad Najib
Published: November 2020

PETRONAS is operating more than 10,000km of offshore and onshore pipeline systems. Inspection and monitoring is one of the element in the Pipeline Integrity Management System (PIMS) where it covers critical activities to ensure high integrity and reliability of business operation for transportation of oil, gas and petrochemical products. This will further identify the risk and manage the pipeline through its operating design life. PETRONAS currently facing new challenges in managing onshore pipeline with girth weld anomaly and stress-strain issue due to geohazard threat.

This paper will describe the inspection options that have been evaluated in addressing stress-strain and girth weld anomaly threats. MFL technology with enhanced inspection capabilities coupled with Geopig are the most reliable technology to ascertain the weldment integrity threat as well as stress-strain of the pipeline.

The replication of inspection tool selection can be applied for offshore pipelines having issues/challenges with respect to geohazards i.e. faults, gas pockets that can induce movement, differential settlement of seabed etc.; and weldment quality verification. The enhanced MFL inspection technology is also collaboration between PETRONAS, local vendor and international inspection company.
A Comprehensive Surfactant Performance Assessment in Harsh Malaysian Reservoir Conditions
Authors: Belhaj Ahmed Fatih , Elraies Khaled Abdalla , Mahmood Syed Mohammad , Tewari Raj Deo , Elryes Ahmed Abdulla
Published: November 2020

Surfactants have the ability to overcome the capillary forces restricting mobilization of oil in the porous media. Generally, the application of surfactants in harsh reservoir conditions has been avoided, due to the challenges accompanying their implementation in such conditions. In this paper, the performance of a mixture of Alkyl Ether Carboxylate (AEC) and Alkylpolyglucoside (APG) was experimentally investigated in harsh reservoir conditions. A Malaysian offshore field with challenging conditions has been studied in this present work, with a reservoir temperature of 106°C and injection water salinity of 32,000 ppm. The investigations were made using surface tension, interfacial tension and partitioning experiments. Surfactant concentration was measured throughout the partitioning test using High Performance Liquid Chromatography (HPLC). The results of the surface tension test showed that the CMC for AEC:APG mixture was approximately 0.13 wt% at 106 °C. IFT results showed that the presence of the surfactant mixture was capable of reducing the IFT between crude oil and brine, and achieve low IFT value (0.035 mN/m) in such harsh conditions. Partitioning test results explained the partitioning behaviour of the surfactant molecules into the oil-water interface. Additionally, surfactant concentration, brine/oil ratio and salinity have a significant impact on surfactant partitioning. The results corresponded to the interfacial tension behaviour, where the lowest IFT value was observed at the highest kp value for the AEC:APG mixture. This concluded that the partitioning coefficient can be directly related to interfacial tension. Furthermore, the increase of the brine/oil ratio as well as the salinity, portrayed an increasing trend of the kp values. The findings of this study showed promising outcomes for future implementation of surfactant flooding in such harsh conditions. By using the proposed surfactant mixture, potential success becomes likely for surfactant flooding application in this study under harsh reservoir conditions.
A Streamlined Multidiscipline Workflow for Pipeline Slugging Assessment
Authors: Zhang Jeff , Jha Saurav , Matuszyk Tim
Published: November 2020

Free spans exist in subsea multiphase pipelines laid over undulating seabed profiles or across continental scarps for offshore field developments. Slug flow induced fatigue damage on the free spans can potentially lead to pipeline re-sizing, more restrictive installation and welding requirements, and limits on life-of-field operational flexibility; these, in turn, have a significant impact on project economics. Slug flow assessments are typically associated with large uncertainties (e.g. flow conditions and span arrangement) and therefore require comprehensive sensitivity analysis to confirm robustness; this can prove time-consuming. This presents opportunities for significant optimisation in workflows to target governing operating scenarios.

This paper describes an integrated iterative approach between the Flow Assurance and Pipeline engineering disciplines to streamline the workflow based on the value or cost associated with changes in input parameters that impact pipeline fatigue assessment outcomes. Case studies on two multiphase pipelines (one with multiple long spans introduced by undulating seabed profile and another featuring a very long span across a continental scarp) are presented to illustrate this design approach.

The results show that early identification of the key pipeline profile features and dominating spans for pipeline slugging fatigue assessments facilitated the Flow Assurance slug flow modelling optimisation and reduced the computational time. Early engagement and alignment regarding pipeline assessment methods and desired slugging data requirements were very valuable for optimising the Flow Assurance slug flow modelling fidelity and also to minimise data processing requirements for both Flow Assurance and Pipeline disciplines. Timely feedback from the Pipeline discipline regarding fatigue accumulation based on screening work performed using an initial slugging data set with a wide flow rate range helped narrow down additional slug flow scenarios to be modelled by Flow Assurance.
Mathematical Model for Predicting the Reservoir Performance of Gas Condensate in Multiphase Flow Systems
Authors: Bapat Sarthak , Akhter Nadeem
Published: November 2020

It is today an undoubted fact that the role of gas condensate systems has increased multifold in the global energy chain. However, the development and production of gas condensate systems remains a challenge to the petroleum industry due to its technical complexity. The production data analysis methodologies that has been followed throughout the industry to estimate gas condensate reservoir performance are conventional technologies which have proved ineffective in forecasting and estimating the gas condensate reservoir performance. The complexities involved in the gas condensate system like liquid dropout, condensate blockage and successive multiphase flow of gas and condensate along with the extensive early-transient infinite acting behavior are the root cause for the failure of the gas condensate system.The similarity method transforms the governing PDE for fluid flow into ODE written in terms of single independent variable that combines time and space. The similarity method provides a unique advantage of solving the obtained ODE without the need for linearization. In this paper, the Boltzmann transformation technique is applied to governing equations for multiphase flow for two inner boundary conditions (constant gas flow rate and constant bottomhole pressure) in linear and radial flow regimes.

The proposed model is validated by using the line-source solution for single phase gas flow above the dewpoint. The proposed analytical solution for flow above the dewpoint pressure reasonably coincided with the line-source solution for flow above the dewpoint, thus, the proposed methodology can be used as an alternative and less time-consuming approach to predict reservoir performance in early transient multiphase linear and radial flow gas condensate systems. The capillary pressure effects considered in the paper were reasonably negligible considering the fact that a negligible capillary difference was used in fluid PVT properties. But was significant when incorporated as an additional pressure gradient term. This however, demonstrated that capillary pressure effects play a vital role in the production data analysis in gas condensate reservoirs. There is no analytical production analysis method developed to date has considered pressure-saturation as a function of a non-dependent dimensionless coordinate in multiphase (oil, gas and water) linear and radial flow systems. This paper aims to fill this knowledge gap by extending a modification of the similarity method to fully incorporate capillary pressure effect in multiphase linear and radial flow systems in which pressure and saturation are simultaneously considered as functions of a dimensionless coordinate.
Stretching Well Engineering Design Standard Limit for Fit for Purpose High Pressure Well Architecture and Delivery
Authors: Abu Bakar Nurul Nadia , Raja Ismail Raja Muhammad , Rameli M. Faisal , Khazali-Rosli Khairul Amir
Published: November 2020

Stretching the engineering limit in order to deliver a high pressure, wildcat well, ZT-1, driven by design optimization and allocated resources which resulted in well cost optimization. For a successful delivery of ZT-1 well, three (3) engineering limit focus area has been identified and tackled with proper risk mitigations for well design optimization. ZT-1 well was designed based on prognosed mid case PPFG, with sensitivity to high case PPFG. As per standard practises, exploration well design need to consider a drill kick tolerance scenario of 25bbls in 8-1/2" hole section. However, ZT-1 opted for a reduced drill kick tolerance of 10 bbls in order to drill the wildcat reservoir in one-hole section, by considering well operational point of view. Second focus area with regards to collapse and triaxial safety factor for 7" production liner. According to company casing design standard, full evacuation to atmospheric load case need to be considered for production casing, which failed in ZT-1 well design. Since the probability of the said load case to occur in ZT-1 well is very low due to its clastic nature, team applied risk based design approach by using actual data from manufacturer to enable the usage of said 7" casing. Third focus area linked to the lower hard cement pressure test value. According to company Pressure Containment and Control standard, casing should be tested after the cement is hard, to the lesser of 70% of maximum internal maximum internal yield pressure (MIYP), or FIT or LOT plus 500 psi, or 200bbls influx from max PP for exploration well. Since ZT-1 well is using the standard G-Cement, the limitation is on cement integrity that does not allow hard cement pressure test to meet the three criteria's, hence derogation was raised. The three-focus area was challenged with calculated risks and proper mitigations in place. For first focus area, real time pore pressure prediction, assisted by FPWD were utilized to assess the operational limits. A robust Total Depth (TD) decision tree criteria were developed, based on PPFG uncertainty and drilling was limited up to drill kick tolerance to safeguard the operations. Second focus area enable us to utilize current OCTG resources hence resulted in cost avoidance. The third focus area is to allow fast decision-making during operation in case of the plug does not bump thus will cause hard cement pressure test. These effective decision frameworks were developed without compromising the well and the cement integrity. The three derogations were raised to stretch the design and operational envelope set by company in order to deliver fit for purpose well design without process safety incident. ZT-1 was drilled safely to deliver the well objectives.
Relative Permeability of Heterogeneous Mixed-Wet Porous Media as Determined by Pore-Scale JBN Based Model
Authors: Mahmud Walid Mohamed , Abdussalam Omran Elhamali , Bennour Ziad , Ermila Mansur
Published: November 2020

Relative permeability data are essential for almost all calculations of fluid flow in porous media. In addition, water and oil relative permeability curves play important roles in characterizing the simultaneous two-phase flow in porous media and predicting the performance of displacement processes. In this work, a pore-scale study of two-phase relative permeability in mixed-wet heterogeneous porous media at different capillary pressure and flow rate is presented.

Multicomponent Johnson, Bossler and Naumann (JBN) method was employed to determine relative permeability using recovery, saturation and pressure results obtained from 3D Eclipse simulation model of a core sample. Mixed-wet states were created by altering the wettability of solid surfaces in contact with the non-wetting phase at the end of the unsteady-state simulation of initially water-wet porous media. JBN relative permeability results were compared to input relative permeability. The JBN results were found to match input data relative permeability especially at lower capillary pressure. The relative permeability of water in the mixed-wet porous media was found to decrease at lower to medium flow rates as water is pinned in smaller pore spaces leading to lower saturation and connectivity in wetting layers. Meanwhile, oil relative permeability increased due to higher connectivity and therefrom greater mobility. On the hand, oil relative permeability of in the mixed-wet porous media decreased at higher flow rates where water connectivity increased the relative permeability of water with increasing water saturation. A new JBN based model was developed to determine relative permeability and good matches were observed between the JBN calculated results and the input relative permeability. Therefore, the model can be utilized for various porous media applications at different wetting conditions.
Connectivity Analysis of Wireless FracBots Network in Hydraulic Fractures Environment
Authors: Alshehri Abdallah A , Shewoil Abdulelah H
Published: November 2020

Fractures Robots (FracBots) are underground IoT (internet of things) wireless sensor nodes designed to be deployed in oil/gas reservoirs to map hydraulic fractures (HF) and monitor in real-time main reservoir parameters including pressure and temperature in real-time. A significant amount of FracBots will be injected inside hydraulic fractures immediately after conducting the fracturing job to gain the required data. They will launch the network connectivity in a fashion of FracBot-to-FracBot to collect, exchange data and transmit it to the base station installed in the wellbore. FracBots technology employs the same concept of the wireless underground sensor network (WUSN), a very capable technology for the applications in hydraulic fractures network. However, developing such technology is exceptionally challenging due to many environmental complications. The main challenges are severe environment, size, and energy limitations which contribute heavily to destroying the quality of the underground wireless communication link. FracBots technology comprises a gateway, a base station (BS), and FracBots. The main role of the BS is to transfer power to FracBots for charging purpose, gather data from FracBots, and finally transmit data to a gateway that send them to a centralized computer for further processing. The function of FracBot nodes is to sense the required data, send it wirelessly among them in multi-hop fashion and then communicate data to BS.

This paper discusses the available wireless communication techniques including electromagnetic waves (EM) and magnetic induction (MI) wireless communication that might be suitable candidates for hydraulic fractures environment. They are compared in terms of the path loss model, path loss parameters, and the advantages and disadvantages of each technique. Moreover, we provide several simulations showing the importance of omnidirectional antenna and the effect of an alignment angle (between the axes of transmitter and receiver) on the path loss of the MI network. Also, we analyze the environmental effects on the path loss inside hydraulic fractures. After studying both EM and MI techniques in fractures environment. We found that the heterogenous environment stiffly influences the EM and MI communications inside hydraulic fractures in oil reservoirs. A hybrid solution that combines both EM and MI communication technologies will be very suitable for such an environment.
Improving Operational Performance Through Digitalization of Standing Instruction to Driller SID
Authors: Hamid Mohd Ridzuan , Meor Hashim Meor M , Norazman Nor Ashraf , Norhashimi Lokman bin , Hamzah M Hadi , Arriffin Muhammad Faris , Mohamad Azlan bin
Published: November 2020

With the current format of SIDs being completely different each project and manually typed in every rigs, improving operational performance based on lessons learned can be quite complicated. The digitalization of Standing Instruction to Driller (SID) can help to overcome this pain point by standardizing and synchronizing SIDs throughout company's operations globally. The paper approaches the subject by introducing a much leaner and seamless method in registering an SID. This can be achieved by having relevant drilling personnel to pick and choose from a common database of SIDs which is frequently updated and verified via web-based platform. The dropdown will be automatically filtered by the application according to the BHA and/or other relevant filter categories chosen. Digital SID drafting process will begin after Notice of Operations (NOOP) has been completed. Information from the NOOP will be populated in the Digital SID platform with all the required associated details including but not limited to BHA designs, hole sections, depths, procedures and lessons learned. These SIDs will have to be agreed and approved by assigned personnel prior to the execution of the operation. Since the solution is capable to create a high quality SID which is readable by both human and machine, it can be integrated with real-time sensors to provide automatic detection for every operation in the SIDs. Therefore, implementation of this Digital SID solution can sustain SIDs consistency across different projects and capable to embed insights in context for future reference. Direct business value created from Digital SID improves process cycle efficiency in a project well life cycle.
Minimum Facility Platform Bring Sub–Commercial Back to Life
Authors: Lophongphanit Chaowarit , Sookkij Kanlaya , Thippayawarn Anucha , Oonkhanond Pariyachat , Medheethunyapong Napa , Theinkaew Sornnarong , Kulavong Passakorn , Hongtong Pongpat , Viriyasomboon Napas , Chotmongkol Prasitsan , Juengsiripitak Jirat
Published: November 2020

Zawtika Project is an offshore gas field located in the Gulf of Moattama, Myanmar with water depth ranges from 120 meters to 160 meters. PTTEPI has operated Zawtika field and brought it to production since 2014 with conventional wellhead platforms (CWP) development. The future prospects are expected to be smaller gas reservoirs which are not commercially developed with CWP. Thus, a minimum facilty platform concept study had been initiated after CWP cannot be economically justified to develop and maintain gas production plateau.

The basic engineering study was conducted on the selected wellhead platform options namely Zawtika optimized conventional wellhead platform (ZOCP) and Zawtika minimum facility platform (ZMFP). These platform types will be chosen for EPCI based on the size of the candidate prospects after the post-appraisal well result is confirmed.

ZOCP is merely a conventional wellhead platform with partial design optimization. On the other hand, ZMFP is a true minimum facility platform. This paper will focus on this type of platform.

ZMFP capacity is reduced to match with the target prospects at 90 MMSCFD gas production. The facilities equipment and intra-field sealine are also reviewed and optimized. ZMFP is expected to reduce the CAPEX approximate up to 20% from (1) minimized well slots (2) commingled the flowlines (3) sweet gas material compatible selection. The unique design of ZMFP is the power supply comes from 100% solar power which is a new implementing concept.

Estimated of the base weight of ZMFP is 17% lower than CWP leading to estimated CAPEX reduction almost 20% compared with CWP. However, due to the stability of platform under the water depth of Zawtika field condition makes the wellhead platform design to be a 4-legged jacket. Small improvement can be done at the jacket which is about 65% of the total CAPEX.

Then an economic evaluation is carried out to compare the NPV of the existing platform design with the improved ZMFP, it found that NPV improve significantly almost 15 %. With the lowering down of the CAPEX, at this stage ZMFP design currently enables 3 sub-commercial prospects to be economically developed. ZMFP design is already selected to implement with the coming Zawtika phase 1D development for 3 wellhead platforms and now it is under EPCI preparation.

Zawtika minimum facility platform demonstrates PTTEPI aims to maximize the resource recovery of the field by developing and monetizing sub-commercial reservoirs. With the above-mentioned objective, a new platform is engineered and designed to sacrifices some options down to its fit-for-purpose facility yet maintain the integrity and environmental friendly designs.
SEAR JIP: A Success Story of Collaboration and How to Improve Equipment Reliability on Subsea Production Systems
Authors: Botto Adriana , Tomar Manish , Ferrier Stuart , Berzins Chris , Casey Mark , Marstrand Jesper , Smith Harvey
Published: November 2020

The award-winning Subsea Equipment Australia Reliability (SEAR) Joint Industry Project (JIP); is a partnership led by Wood with participation from a group of operators namely Chevron Australia, ConocoPhillips, Inpex, Santos, Shell Australia and Woodside. Now delivering Phase 6, the JIP is focused on collaboration and knowledge sharing in order to improve the competitiveness of Australia's oil & gas industry by addressing critical challenges associated with subsea equipment failing prematurely.

This paper will provide an overview of the SEAR JIP and outline lessons learned, and value created. Results from the reliability database will be presented as well as findings from ongoing field trials on the four living laboratories deployed in different geographic locations and water depths in Northern Australia. This paper will also discuss challenges associated with subsea controls umbilicals that are prone to emit hydrogen gas and fluids at the surface facility through the electrical junction boxes.

The end goal of SEAR JIP is to develop an industry wide recommended practice, with regional guidance notes for equipment and field design. The recommended practice is intended to reduce operating cost for existing and future projects, while identifying technologies that are specific to Australian waters.
Identification of Fracture Properties in Shale Oil Reservoirs by a Well Testing Model: A Case Study
Authors: Jun Pu , Qin Xuejie , Chen Zhiming , Shi Luming , Wei Yi , Chen Haoshu , Meng Meiling , Gou Feifei
Published: November 2020

In the shale oil reservoirs, the horizontal wells with large-scale fracturing treatments have been the most effective tools to enhance oil productivity. After large-scale fracturing treatments, many micro-seismic data showed that the fracture networks are generated in the reservoir along the wellbore. Understanding the complex fracture properties is the primary step for fracturing evaluation and productivity estimation. Thus, an efficient approach is needed to estimate the fracture properties. To improve this situation, a well-testing approach was proposed in this work to identify the fracture properties. This work was organized as follows: (1) developing a well-testing model of multiple fracture horizontal well (MFHW) including reservoir flow equations, fracture flow equations, and mass balance equations, (2) solving and verifying the proposed model using boundary element method, superposition principle, and numerical approach, (3) applying the well-testing model to investigate the pressure transient behaviors, and (4) estimating the fracture properties of shale oil wells from the Junggar Basin.
Compensating the Effect of Shallow Gas Cloud for Seismic Time-to-Depth Conversion
Authors: Azmi Afifah , Mad Zahir M Hafizal , Ishak M Anwar , Mohd Adnan Amar Ghaziah , Megat Ismail Megat Iskandar , Che Lah Che Zurida
Published: November 2020

Shallow overburden, specifically gas cloud, will create velocity anomaly. The anomaly will make the events underneath to be disrupted, thus affecting the seismic reflectors. Velocity model build from the seismic with the existence of anomalies will give us an inaccurate velocity estimation. Velocity model is crucial for various processes and one of it is for time-to-depth conversion. Therefore, it is very critical to have an accurate velocity model in order to provide us actual subsurface structures and lead us to the true reservoir location. In this paper, we will explain on our proposed approach to condition the velocity model with gas cloud problem. The robustness of the method was tested by using different velocity models for time-to-depth conversion and the results were analyzed. The criteria of the best depth map are conformance with geological structures, accurate well tie with the existing well and minimal residual errors within acceptable range. From the study conducted, we have proved that the seismic velocity with gas cloud correction provides the best depth map with minimal residuals.
Road Map Towards the Integrity Assurance of Composite Repairs in Offshore Facilities
Authors: Choo Wei Lee , Arifin Rosman , Mohd Ramli Siti Haslina , Syed A. Hamid Syed Muhsin
Published: November 2020

Composite repairs on pressurized equipment, piping and pipeline in offshore facilities have become increasingly common due to its benefits in terms of cheaper cost and faster repair time, which generally leads to avoidance of potential production downtime. PETRONAS has developed a roadmap which is in alignment with currently available international code and standard references on integrity assurance program for composite repairs, such as ISO 24817. This roadmap seeks to manage the risks involved during all phases of a composite repair program (i.e. pre-installation, during installation, post installation and periodic monitoring). It focuses on five primary elements namely: 1. inspection tools evaluation including desktop evaluation, technology demonstration, pilot program implementation, and summary of inspection methodologies, 2. Governance establishment covering development of company guideline, 3. Competency management enhancement via personnel training, certification schemes, and roles and responsibilities establishment, 4. Procedure, planning, implementation & monitoring, and 5. Continuous improvement via assurance programs and management review. This paper summarizes some of the efforts undertaken, and future plans to support each of the abovementioned phases as part of a comprehensive solution for the integrity assurance of composite repairs in offshore facilities.
Pipeline Integrity Management and the Invent of Analytics
Authors: Mohd Ali Napiah Mohd Nazmi , Abu Bakar Mohd Hisham , Mat Tuselim Ahmad Sirwan
Published: November 2020

Managing pipeline integrity revolves around abundance of data and information from monitoring of safe operating limits, inspections and maintenance. Those data and information may come from real-time/on-line systems, manually input ad-hoc, manually input from inspections and maintenance carried out on a particular pipeline. The oil and gas pipeline industry have sort of mature with respect to having a software/tool in aiding and assisting personnel in performing risk, fitness-for-service, repair assessments, and executing management of change for a pipeline system; and many more assessments/analyses.

Nevertheless with the invent of analytics, there is strong need to explore the new ways of working with those abundance data and information OR maximising the utilisation of the data and information for the benefit of assessing or evaluating pipeline's risk and integrity to predict 'accurately' risk and integrity so that specific and cost-effective actions and mitigations can be deployed within a stipulated period of time.

In those regard, PETRONAS is actively working with industry to establish predictive analytics for critical offshore and onshore pipelines' threats/anomalies i.e. internal corrosion and free span for offshore; and external corrosion and geotechnical hazard for onshore. This paper will dwell on the principles, concepts and methodology of predictive analytics tools for the development. It is envisaged that eventually those threats/anomalies will be analytics-managed to eliminate unwanted incidents to PETRONAS's offshore and onshore pipelines. In addition, analytics-pipeline integrity management will also likely to provide 'accurate' prediction of 'future' pipeline integrity.
An Autonomous Underwater Vehicle with Remote Piloting Using 4G Technology
Authors: Newell Todd , Gayathry Hema
Published: November 2020

Conventional remotely operated vehicles (ROVs) are tethered with umbilical cable and are distantly controlled by a vehicle operator. The ROV control system requires constant monitoring due to complexities caused by unknown nonlinear hydrodynamic effects, parameter uncertainties, and system inflexibilities (conventional ROV systems cannot be preprogrammed and can only be operated at a limited distance due to tether length limitations). Conventional operators are unable to dynamically compensate existing vehicles for operations that need further efficiency, flexibility in movement, and a non-disruptive data transfer.

To solve these challenges, Oceaneering introduced its next-generation resident ROV, which provides a new level of flexibility and efficiency while performing common ROV tasks, such as surveys, inspections, valve and torque tool operations, and manipulator-related activities. The next-generation resident ROV is sustained by a docking station at seabed, and its design features hybrid functionality that enables it to operate in two modes: remotely piloted via tether to provide real-time control or by battery power, operating autonomously and without a tether.

Using a next-generation resident ROV decreases the number of vessel days required to complete operations, reduces carbon footprint, and minimizes mobilizations. It enables operators to expedite subsea interventions in strategic locations and overcome challenges associated with weather windows. The next-generation resident ROV also improves operational versatility by offering tethered and autonomous operating modes and significantly improved depth ratings that enable it to access difficult-to-reach locations. Vehicle operations are supported by our remote piloting and automated control technology (RPACT) and Onshore Control Center. By delivering a single-source solution, users are able to streamline operations, adopt standardization across projects, and reduce both cost and risk. The operational flexibility of the next-generation resident ROV is driven by proprietary supervisory control software. Whether the vehicle is operating with or without a tether, this software provides complete vehicle control, autonomy, payload and sensor control, topside mission planning, and situational awareness. Oceaneering's proprietary supervisory control software provides key vehicle piloting improvements, including an unprecedented level of awareness in crowded subsea fields.

The next-generation resident ROV can also be programmed to make piloting decisions without the need for human pilot control, such as for avoiding obstacles or responding to changing plans. By taking advantage of the known subsea environment, proprietary software enables pilots commanding the next-generation resident ROV to be available for other tasks. This combined software and vehicle configuration makes it possible to perform more tasks, faster and more safely than ever before.
Twelve Years Field Applications of Offshore Heavy Oil Polymer Flooding from Continuous Injection to Alternate Injection of Polymer-Water
Authors: Pan Guangming , Zhang Lei , Huang Jianting , Li Hao , Qu Jifeng
Published: November 2020

South part of NN reservoir, located at Bohai Bay of China, has reservoir characteristics of complex oil-water contact system, thin single pay zones of 6~8 m and heavy oil viscosity with 413~741mPa·s. At initial natural energy production stage, daily oil of horizontal well reached 21~ 35m3/d. Due to complex oil-water relationship and high formation oil viscosity, oil production rate of whole reservoir decreased from 0.6% to 0.3% after one year.

Considering increasing viscosity of injected fluid and reducing the difference of water-oil mobility ratio, polymer flooding with continuous injection mode was carried out since 2008, and its initial good application effect demonstrated polymer flooding was suitable for the thin heavy oil reservoir. However, the problem of gradual decreasing injection ability and oil increment occurred after eight years of continuous injection.

A series of physical experiments indicated that profile inversion was inevitable for long PV continuous injection, which results from the difference in the variation of resistance coefficients in high and low permeability zones. The phenomenon of profile inversion was also found in field application by water profile test data over the years. It became critical to inhibit profile inversion for the following injection stage. Two kind of modes including continuous and polymer-water alternate after long PV continuous injection were considered by double tube contrast experiments. Results showed that alternating injection performance was better than continuous injection, low permeability tube had higher oil recovery and larger flow fraction in alternating injection, which demonstrated profile inversion was inhibited in alternating injection mode and more fluid flew in the low permeability tube. After alternate injection was carried out in target reservoir in 2016, the injection rate was increased by 20% because of lower phase viscosity. The average resistance coefficient of alternating mode reached as high as 1.74, which was similar to continuous injection process (2.06). Around the three injection wells, there are nine wells increasing the oil production, and incremental oil production for single well has reached 0.45×104m3~2.12×104m3. The total daily oil production was enhanced by 30%, and the water cut was decreased by 8%. During alternating injection process, polymer agent dosage was reduced by 50%, and operation cost of barrel oil was reduced by 85%, which showed good economic benefit.

Polymer flooding has been considered a suitable method for reservoirs with viscosities up to 150 mPa·s. Our practice confirmed again such alternating injection of polymer-water development techniques were also effective and economical for heavy oil fields, even in the offshore oil fields. Polymer flooding pilot of initial continuous and then alternate can provide certain technical reference for similar reservoirs.