bluuebunny/crossref_metadata_2025 huggingface dataset:
Resource-Limited, Collaborative Pilot Intervention for Chronically Homeless, Alcohol-Dependent Frequent Emergency Department Users
Authors: McCormack Ryan P. , Hoffman Lily F. , Wall Stephen P. , Goldfrank Lewis R.
Published: October 2013

We introduced case management and homeless outreach to chronically homeless, alcohol-dependent, frequent emergency department (ED) visitors using existing resources. We assessed the difference in differences of ED visits 6 months pre- and postintervention using a prospective, nonequivalent control group trial. Secondary outcomes included changes in hospitalizations and housing. The differences in differences between intervention and prospective patients and retrospective controls were −12.1 (95% CI = −22.1, −2.0) and −12.8 (95% CI = −26.1, 0.6) for ED visits and −8.5 (95% CI = −22.8, 5.8) and −19.0 (95% CI = −34.3, −3.6) for inpatient days, respectively. Eighteen participants accepted shelter; no controls were housed. Through intervention, ED use decreased and housing was achieved.
Multi-Realisation Full-Field History-Matching For CBM Resources a New Approach with Global Optimisation Coupled with Geo-Statistical Filtering
Authors: Alessio Laurent D. , Nasri Haitham , Pan Sophoana , Clement Lee Thian , Peng Chua Ket
Published: October 2013

CBM reservoirs are known to exhibit a large degree of variability in production characteristics and performance at the inter-well space. This is a consequence of the variable nature of the fractured permeability network, but also other important measurable parameters such as gas content, isotherms, and much more difficult to measure ones such as porosity, relative permeability and matrix shrinkage.

Once the field is on production for a period of time, operators often wish to perform a history-match of the asset, to determine the remaining production potential, and the most adequate future development activities. Traditionally, this exercise is conducted with numerical models.

An unfortunate reality of history matching is the existence of multiple solutions, which will behave differently when forecasted in the future. This is a consequence of the fact that multiple parameters influence the match and their inter- dependency produces effects that are may compensate each other; many of these parameters are generally either poorly understood and/or highly variable at the inter-well scale. In addition, most of the critical parameters for dynamic performance are not measured in well logs, nor seismic (which often is not available) – only through more expensive activities such as coring and production testing.

Given this reality, using the classical conventional gas workflows for the implementation of 3D history matched models for CBM fields is shown to be inefficient since the transition from the reservoir characterization to the static modelling is insufficiently constrained, and doesn’t include the production performance of the existing wells.

In order to adapt the classical workflows to the complex case of CBM fields, we introduce in this paper a filtering process based on geo-statistical constraints which uses the single well stochastic history matches to generate field matches and invest the matched drainage areas on the generation of "average properties" maps.

These maps can thereafter be used as input into the infill drilling analysis and the resource assessment studies, but also introduced into the static model to condition the property model, and achieve a field history-match which much more closely reproduces the production behavior of individual wells.
Risk Assessment Technology Research on CO2 Injection Wellbore
Authors: Feng Wang , Yu Liu Chang , Qing Li , Kuiwu Li , Deping Zhang
Published: October 2013

CO2 flooding experiment is conducted on the old well after water flooding, without taking into account such designs as CO2 corrosion control and gas seal. There are more wellbore weak links. In order to meet the demand of the long-term safe CO2 flooding, safety risk assessment is required.

Wellbore risk assessment process and evaluation template is established.. Integrated application of cementing quality detection, casing condition and annual pressure evaluation technology, safety risk assessment technology of CO2 flooding has formed and established wellbore risk assessment on CO2 flooding wells converted from water flooding mature wells.

This technology has been widely applied in CO2 flooding test in Daqinzi, jilin oilfield, comprehensively evaluating safety condition of old wellbore, screening suitable CO2 flooding well and assessing annulus pressure condition of injection well to ensure the long-term safe CO2 flooding.
Production Maximization and Sustainability Based on Operational Optimization & Reliability Enhancement of Wellhead Compressors
Authors: Albani Danilo , Foglie Giangrazio Delle , Pichierri Giacinto Paolo , Khan Ahmad Ali , Ferretti Carlo , Sattar Abdul
Published: October 2013

Eni Pakistan limited, an oil and gas company, is the operator of gas processing plant which receives raw gas from two different fields, Field A with 13 wells and Field B with 03 wells, in order to process gas in three parallel processing trains to meet sales gas specification.

The Field A gas field development was sanctioned in November 2000 and came into full production in March 2003 while Field B first gas was achieved in 2008. In order to meet the country’s emerging gas demand and to counter far the natural reservoir depletion, 10 Wellhead Compression Packages (09 at Field A and 01 at Field B wells) were installed with the aim of exploiting the already discovered reserves and production optimization by extending the plateau and field viable life. Two standard sizes of reciprocting Wellhead compression packages were installed with Nominal capacities of 3.3MW compressor for 110 MMSCFD and 1.9MW compressor for 74 MMSCFD flow at a minimum suction pressu e of 100Psiig with discharge pressure of 850 Psig. Each compression unit has its own power generation and control / safety systems.

The operational challenges of depleting fields and soaring demand of productiion sustainability requires operational optimization through compressors reconfiguration integrated with a comprehensive and effective Asset Integrity and Reliability Management system. This laid the foundations of operational excellence though a proactive result oriented approach. The two pronged approa hes were based on CE (Cause and Effect) which resulted in achieving a reliability factor of 98.75% over cumulative operational span of more than 200,000 hours.

This paper shares the lessons learned in the due course of Operational life, emphasizing on the best maintenance practices along with the process of optimization campaign for operational efficiency and to sustain production. Nevertheless, the integrated approach and collaboration between reservoir, operations, maintenance and project team was the key to achieve such excellent results. A systematic methodology from proposal to execution of reconfiguration activities is also briefly explained.
Prediction of Mobile Water in a Tight Gas Sandstone Reservoir using NMR and Fractional Flow Model
Authors: Anantawati M. , Bulgauda S.
Published: October 2013

One of the objectives of petrophysical interpretation is the estimation of the respective volumes of formation fluids. With traditional interpretation using conventional openhole logs it is only possible to determine the total amount of water. The challenge is to determine the volumes of bound water(clay-bound and capillary-bound) and free water. At the moment, NMR is the only measurement that can help distinguish the volumes of each water component (clay-bound, capillary-bound and mobile), using cut-offs on T2 (transverse relaxation time). However NMR interpretation also requires information on reservoir properties. Alternatively, steady-state relative permeability and fractional flow of water can be used to determine the potential of mobile water.

The study area, located in the Cooper Basin, South Australia, is the target of a planned gas development project in the Patchawarra formation. It comprises multiple stacked fluvial sands which are heterogeneous, tight and of low deliverability. The sands are completed with multi-stage pin-point fracturing as a key enabling technology for the area.

A comprehensive set of data, including conventional logs, cores and NMR logs, were acquired. Routine and special core analysis were performed, including NMR, electrical properties, centrifuge capillary pressure, high-pressure mercury injection, and full curve steady state relative permeability. A fractional flow model was built based on core and NMR data to determine potential mobile water and the results are compared with production logs.
Selective Acid Stimulation Using Two Different New Technologies-Case Histories from a Saudi Arabian Oil Field
Authors: Baruah Keshab , Al-Otaibi Nashi M. , Al-Ghamdi Hammam M. , Al-Subaie Fehead M.
Published: October 2013

Carbonate acidizing is very common in the oil industry. In the case of mature heterogeneous reservoirs with different permeabilities and high water cut, stimulation in these reservoirs can be a real challenge. Major technology developments in well stimulation over the last few years are evident in numerous publications. Two new technologies currently in the spotlight were applied in a matured SaudiArabian oil field.

This paper addresses case studies of selective stimulation using a fiber optic enabled coiled tubing (FOECT) system combined with smart chemicals where real-time distributed temperature sensing technology facilitated instant decision process of temporary zonal isolation, fluid placement and treatment efficiency evaluation. The paper also describes another acid stimulation technology used in the same matured field where the completion is equipped with a multistage stimulation completion designed toselectively treat different reservoir sections using a ball drop mechanism. Candidate selection, treatment design, execution, and post job evaluation for both the technologies will be discussed in the paper. Lessons learned and experience gained to optimize similar future jobs will be included in this paper.
Managed Pressure Drilling - A Solution for Drilling the Challenging and Un-Drillable Wells in Vietnam and South East Asia
Authors: Gedge Ben , Dalgit Singh Harpreet Kaur , Refugio Elsofron , Ta Quoc Bao , Bot Nguyen Viet
Published: October 2013

Managed Pressure Drilling (MPD) has been deployed in Vietnam for six (6) years since 2007 to address a number of drilling and reservoir challenges, and has delivered considerable success in many cases. Twenty five (25) separate projects have been performed over the six (6) year period, in a range of formations and with different types of rigs.

The main application of MPD Technology has been in the following reservoir and formation types where the challenges are being encountered: granite basement, fractured and vugular carbonates, High Pressure High Temperature (HPHT) and over pressured clastics. MPD has not been applied as yet in deepwater, but its application is being viewed with interest by operators in Vietnam planning deep water operations, following its successful deployment in other regions of South East Asia.

The types of rigs on which the technology has and is being applied are all offshore, and include Jack-Ups, Semi-Submersibles and a Platform rig supported by Semi-Submersible Drilling Tender Assist barge.

The paper will examine and discuss the different procedural approach of MPD Technology used today including Constant Bottom Hole Pressure – Equivalent Circulating Density (ECD) management, Early Kick Detection, and Pressurized Mud Cap Drilling (PMCD). MPD has mainly been used in reservoir sections, but by no means exclusively, for example in carbonate loss zones which may or may not contain gas, for Rate of Penetration (ROP) gain and ECD management in intermediate hole sections.

Three (3) case histories will be presented within the paper addressing the different applications and formations in which the technology has been applied in Vietnam. This includes achieving an additional 800 meters of a granite basement reservoir section, reducing the fluid losses, improving ROP, reduction of Non – Productive Time (NPT) and post drilling clean up, by 60 – 70%, compared with previous wells in the field. The drilling of HPHT and over pressured clastic formations with an extremely narrow kick – loss tolerance, where there is a high risk of fracturing the formation or inducing a serious kick, if the hydraulic profile of the well is not successfully managed.

The pre-planning, engineering, equipment utilized, and adaption of the drilling rig to facilitate the successful deployment of MPD Technology will all be discussed, to clearly demonstrate what is required to deliver a successful MPD project and the well objectives.
Alternative Vertical Drilling Technology Delivers Premium Performance While Reducing Operating Costs
Authors: Neil P. , Herrington D.
Published: October 2013

Maintaining verticality in today’s challenging drilling applications is of critical concern. The vertical section is increasingly important in anti-collision situations, as well as in extended reach directional wells where weight transfer through tortuous vertical sections can make the difference in calling Target Depth (TD) early of not. Excessive dogleg severity compromises well completion and adds costs that erode the profitability of operations and ultimately production of the well.

To date, a limited number of options have been available, with low cost, low performance systems at one end of the scale and high cost, high performance systems at the other. Every day we are looking at more unconventional reserves and tighter budgets to work within. To align with these goals, we must find a solution that provides the quality performance through a technology that fits today’s fiscal demands as well.

Conventional vertical drilling approaches such as control drilling, drilling with bent housing motors, and rotary steerable systems have notable drawbacks. Poor performance and efficiency on the low end and exorbitant cost on the high end push us to a new solution.

A technology is now commercially available that provides all the performance of the higher cost Rotary Steerable System (RSS) while offering a better economic position for operators. With this new technology, borehole quality no longer has to be sacrificed for cost. The technology is fully autonomous and recent performance data shows that a major operator has utilized this technology for a reduction in costs of over 20% versus conventional technology while providing comparable rates of penetration and borehole quality.
Successful Casing Drilling Experience with Premium Connection for Production Casing Application on a Subsea Well
Authors: Ong G. , Yamaguchi S. , Imai R.
Published: October 2013

This paper discusses the casing design and connection selection process where the first Casing while Drilling (CwD) technology was deployed in a subsea exploration well in the Dampier Sub-Basin, Northwest Shelf offshore Australia to overcome the problematic drilling operations while drilling through the highly porous "Bare Sands" which often led to severe loss circulation. This was the first attempt for the operator to deploy a newly developed Threaded and Coupled (T&C) Type Premium Connection on 9-5/8-in. 47 ppf L80 for production casing application with CwD technology. Hence, the process of identifying and mitigating risks when applying new connection technology in a highly critical application was vetted thoroughly.

It is understood that not all premium connections are suited for such application to meet key selection criteria, such as fatigue performance, torque resistance and being able to maintain gas sealability whilst under severe well load conditions including tension and compression loads after being subjected to severe cyclical bending stress during CwD operation. In order to ensure that the connection survives the continuous abuse during CwD in order to meet the objective of the well, a newly developed T&C connection from VAM® was selected for this challenging application. The connection is characterized by easy field make up, exceptionally high torque resistance, excellent gas sealability which is in compliant with ISO 13679 CAL IV and it comes with superior fatigue resistance attributed to the new and innovative connection technology.

The casing drilling operation was completed from a semi-submersible rig reaching a world record depth at 1,906 m in technical limit time with drilled interval of 1,710 m. The successful deployment of 9-5/8-in. 47ppf L80 with this newly developed premium connection for production casing opens up a new chapter for similar CwD applications in the industry.
Estimation of Porosity, Permeability and Water Saturation in Tight Sandstone Reservoirs Based on Diagenetic Facies Classification Method: Case Studies of Chang 8 Formation in Northwest Ordos Basin
Authors: Hua Yang , Yu-jiang Shi , Shaanxi Xi'an , Liang Xiao , Zhi-qiang Mao , Cheng Feng , Gao-ren Li , Hao-peng Guo , Jin-yu Zhou
Published: October 2013

Porosity, permeability and water saturation cannot be effectively estimated from conventional logs by using the classical methods in tight sandstone reservoirs due to the complicated mineral components, pore structure and strong heterogeneity that caused by the diagenesis in the Chang 8 Formation of northwest Ordos basin, In this paper, based on the difference of diagenetic facies, effective formations are classified into three types, the relationships between conventional density log and core derived porosity, core derived porosity and permeability are established in every type of formation. In the meanwhile, the laboratory resistivity experimental results are also classified based on the diagenetic facies, and the cross plots of porosity and formation factor, water saturation and resistivity index are drawn to obtain the rock resistivity parameters, separately. These results illustrate that for formations with different diagenetic facies, the matrix densities are diverse, the relationships between core derived porosity and permeability are also different, and they contain different rock resistivity parameters. By using the diagenetic facies classification method and chart proposed by Xiao (2012), the effective Chang 8 Formation is classified into three types, and the corresponding models are applied to calculate porosity, permeability and water saturation. Comparisons of estimated porosity, permeability and water saturation by using the proposed techniques and the core derived results illustrate that the proposed techniques are valueable in tight sandstone reservoir parameters evaluation.
Effects of Precipitation Inhibitor on ASP Performance in Carbonate Reservoirs
Authors: Kalwar Shuaib Ahmed , Elraies Khaled A.
Published: October 2013

Field performance of ASP technique has achieved technically successful and economically feasible results for sandstone reservoirs. However, little attention has been given to ASP application in carbonate reservoirs. The main constraint of ASP flooding in carbonate reservoir is the presence of calcite, dolomite and calcium sulfate minerals. These minerals react with the added chemicals to form insoluble salts known as precipitations. Therefore, an Alkaline-Surfactant-Polymer formulation was developed by incorporating acrylic acid as a precipitation inhibitor or protection agent to overcome the precipitation problems caused by reservoir minerals and brine compositions. The performance of the Acrylic Acid (AA) with an ASP formulation was estimated using sodium metaborate and three types of high tolerant surfactants for possible screening. Feasibility of applying AA with ASP formula was demonstrated by comprehensive fluid-fluid and fluid-rock compatibility tests. Static and dynamic experiments were conducted for monitoring precipitations and permeability reduction using a limestone core samples. Hardbrine composition of 59,000 ppm was used to prepare the ASP formulations in the presence and absence of AA. As results, all chemicals including, alkalis, surfactants, and polymers were incompatible with the hardbrine used in this study. Precipitations were generated from the first day of mixing. However, the presence of acrylic acid showed excellent properties in preventing precipitations and all solutions remained clear for 30 days at 80°C. The optimum acid concentration was found to be proportional to alkali concentration using acid to alkali weight ratio of 0.6:1.0. Using the optimum acid to alkali ratio, the permeability reduction caused by precipitations was significantly improved. This might add more advantages to ASP process in which hardbrine water can be used instead of softened water.
Investigation on Corrosion of Insulation Tubing Steel in HTHP Steam and Flue Gas Co-Injected to Enhance Heavy Oil Production
Authors: Zhaoxia Dong , Liguo Zhong , Yicong Tian , Yanchao Wang , Yongtao Sun , Lichang Zhao , Tao Lin , Wenkai Lu , Mingyou Yu
Published: October 2013

Co-injection of steam and flue gas is potentional to improve heavy oil well production. For a typical steam and gas co- generator, the flue gas content is about 10wt%-30wt% in general, the temperature usually ranges from 200℃ to 350℃ (regulated by fuel and water injection rate), and the injection pressure is up to 20MPa. More attention has to be attached to the corrosion of insulation tubing in the HTTP steam and flue gas comprised of CO2, N2 and residue O2. In this work, corrosion performance and inhibition with some additives of the insulation tubing steel in HTHP fluid of steam, CO2, N2 and residue O2 were investigated by weight loss experiment with alloy reactor. The results showed that there are another peak at 200℃ except the corrosion rate peak at 60℃ for CO2 and O2 corrosion, the corrosion rate of steel in co-injected fluid is enhanced at higher temperature. The corrosion principles are related to production of FeCO3 and Fe2O3 under different conditions. At higher temperature, corrosion rate could be reduced with addition of corrosion inhibitor and/or deoxidizer, for example, more than 90% reduction in corrosion rate could be obtained with addition of 2000mg/L selected corrosion inhibitor at 200℃. Additionally, the field testing cases show significant corrosion inhibition of insulation tubing in co- injection of steam and flue gas with addition of corrosion inhibitor.
Integrated Regional Interpretation and New Insight on Petroleum System of South Sumatra Basin, Indonesia
Authors: Carrillat A. , Bora D. , Dubois A. , Kusdiantoro F. , Yudho S. , Wibowo E. , Musri M. , Tobing J. C. , Gomez T. P. , Xue F. , Balasejus D. , McDonald T. D. , Audemard P.
Published: October 2013

South Sumatra Basin is an inverted post-arc Tertiary basin, which has a complex evolution history from late Eocene- Oligocene extension to late Miocene and Pliocene compression. To evaluate the overall basin prospectivity, a regional analysis is conducted at 8 stratigraphic levels from pre-Tertiary unconformity to Pleistocene. An integrated interpretation including more than 1400 2D seismic lines, 4 seismic 3D surveys, and formation evaluation from 80 key wells is used to run the basin analysis. A series of regional seismic transects are defined through key wells and major structural elements to capture the characteristics of structural styles, lithostratigraphy and hydrocarbon distribution across the basin.

Structural restorations unravels the timing of fault activity showing basin rifting until ~23 Ma with main depocenters in Benakat Gully, Limau Graben, Central Palembang and Lematang Depression followed by sagging until 14.6 Ma. The compressive event is recorded from 5 Ma to present day. The buckling of syn-rift sediments suggests shortening expressed by inversion and fault reactivation rather than thrusting. Review of the source rock data, reservoir distribution, hydrocarbon phase and source to reservoir correlation data are evaluated in perspective of the basin configuration in order to select sections for basin modeling. The modeling results show onset of expulsion varying from ~10-15 Ma from Lemat Fm. and Talangakar Fm., and 5 Ma from Telisa Fm. Modeling suggests that Talangakar Fm. reservoirs are completely filled, whereas Lemat Fm. reservoirs are partially filled due to limited lateral and downward migration. Baturaja Fm. reservoirs in proximity to depressions are filled, and partial charge risk away from kitchen area. Most of the hydrocarbon are generated, expelled and accumulated between sedimentation of Lower Palembang Fm. to inversion time (10-5 Ma). The subsequent inversion is likely to have re-migrated hydrocarbon in Talangakar and Baturaja reservoirs along Benakat Gulley and associated fault bound folds.
The Next Generation Petroleum Production Technology; Early Predictive Well Health (WH) Meta Monitoring Tool (ARTAM-WH)
Authors: Goldschmidt Peter , Crawley Charles , Bashirul Haq , Palanisamy Santhosh
Published: October 2013

Maintaining stable operations with high recovery requires routine checking of individual Well Health (WH). A well performing as expected is healthy. It is essential for efficient field operation to detect WH issues early that may reduce overall recovery. An early predictive and WH meta-monitoring tool is highly desirable. Our new approach is designed to provide early identification of existing or developing WH issues - precursors to WH problems if not addressed. ARTAM-WH utilizes in-situ monitoring systems coupled with static data, conducts preliminary analysis and proper cross checking and then notifies engineers/operators. Differentiating this approach is that it is not looking at small data sets but a large palate including both static (the well construct) and dynamic, current performance versus performance expectations. ARTAM-WH provides supporting evidence of WH Issue to the appropriate stakeholder. Notification includes the necessary and sufficient evidence derived from approximate reasoning algorithms combining multiple variables to identify possible issues and testing the WH hypotheses. ARTAM-WH aims to provide early warning signals, including substantiating evidence, to engineers/operators managing large volumes of data generated within monitoring systems; lowering operating costs and expediting the decision- making processes. Reducing time to action; improving operational effectiveness; increasing production due to reductions in unexpected downtime and previous lost profit opportunities being captured. This new approach frees up engineers/operators time to focus on higher priority activities such as developing solutions. Early identification of emerging problems also allows for the ability to handle those problems through normal planning rather than emergency fixes.
Integrated Reservoir Characterisation for Thin Waterflooded Carbonate Oilfield in Oman
Authors: Limin Zhao , Longxin Mu , Haiying Han , Guoliang Zhao , Rui Guo , Jun Wang
Published: October 2013

Reservoir characterization is the most important in building robust geological and simulation models. The improvement in reservoir characterization enhances the understanding of the reservoir heterogeneity and reduces the uncertainties on field development. This can be achieved with better descriptions of reservoir frameworks and properties. D oilfield is located in northwest of Oman and it has been rejuvenated by water injection since 2001 using horizontal well line driving pattern. In this paper, comprehensive reservoir characterizations of thin Early Cretaceous Upper Shuaiba limestone reservoir of this oilfield were carried out based on the current data for guiding the further adjustment plan and achieving better development results.

Horizontal well correlation modes were defined based on the reservoir boundary encountered by the horizontal trajectory to construct the reservoir framework. The interpretation and identification of small faults and fractures were identified based on seismic data, FMI logging, core data and production data. Under the guidance of depositional model, data from horizontal wells has been fully used in combination of pseudo-wells to build the 3D geological model to accurately delineate small faults, reservoir boundaries and property distributions. Based on fracture parameters derived from static and dynamic data, fracture network model and equivalent permeability model have been built constrained by fracture density. The intelligent reservoir characterization provides a reliable geological guidance to ensure the reasonable placements of infill horizontal well trajectories through the reservoir. The real horizontal drilling indicates that the oil reservoir accounts for 90% of the total horizontal section for D oilfield.
Integrated Study of Reservoir Characteristics of a Shale Gas Reservoir: A Case Study from Sichuan Basin of China
Authors: Feng Yang , Zhengfu Ning , Qing Wang , Huiqing Liu , Shidong Zhang , Hongmei Liao
Published: October 2013

The Lower Cambrian Niutitang Formation is an organic-rich siliceous mudrocks which is widely considered to be a potential shale gas reservoir in Sichuan Basin of southwest China. An integrated study was performed to characterize the reservoir characteristics. A series of tests were conducted on core samples including organic geochemistry, mineralogical, petrophysical and mechanical properties. A deep insight into the characterization of pore structure in shale reservoir was analyzed by field emission scanning electron microscope, gas adsorption and high-pressure mercury injection.

The results show that Niutitang Formation shale reservoir has the potential for gas exploration and production due to organic matter rich, moderate porosity and high brittleness. The Niutitang formation is of great thickness and the total organic carbon content ranges from 0.16% to 9.15% with average of 3.56%. The porosity of shale samples is from 1.26% to 9.85% with average of 5.78%, and the pulse permeability of matrix is from 320 nD to 890 nD. The total content of brittle minerals (quartz, feldspar and carbonate) is over 70%, and the formation is characterized as rigid and brittle for high elastic modulus and low Poisson's ratio. There are five types of pores in shale: organic nanopores, pores of clay minerals, intraparticle pores of matrix minerals, intragranular pores from microfossils, and microfractures, and the chief are organic nanopores and pores of clay minerals. Nanopores with pore diameter less than 50nm provide the main pore surface area and pore volume, which indicates they are the main place for hydrocarbon adsorption and storage. These results will provide a basis for further evaluation of the hydrocarbon potential of the Lower Cambrian Niutitang Formation shale in the Sichuan Basin.
Subsea Completion Operated by Longleg Jackup Rig
Authors: Prasetyo Adi
Published: October 2013

Kangean Energy Indonesia (KEI) on behalf of EMP Tbk, JAPEX and Mitsubishi Corporation drilled and completed five (5) Terang high-deliverability gas wells utilizing a Jackup rig in 2011. Terang field, as the Phase-1 of Terang, Sirasun and Batur (TSB) fields’ gas development project was put into production in 2012. TSB fields are located at east of Surabaya and north of Bali Island with the water depth ranging from 300 ft to 750 ft. Terang field is located in the western part of the complex with the water depth of 300 ft.

The challenge of this project was to drill and complete subsea wells by a jackup rig which is equipped with only surface BOP. This is a new endeavor to perform subsea well completion using a jackup rig in Indonesia and finally it is a successful operation to drill and complete the five Terang wells using a long-leg jackup rig. Terang field had been developed by drilling and completing five (5) subsea production wells. Special additional devices were designed and attached to the jackup rig to enable drilling the subsea wells as well as perform batch drilling easily. These are High Pressure (HP) drilling riser and Suspended Texas Deck (STD), which is an additional deck suspended from the rig frame.

The STD was designed and introduced to promote operational safety by supporting safer and practical installation of the surface BOP equipment and also yielded a time-saving by reducing the handling time of HP drilling riser. These added features had proven to reduce operations time when two-well batch-drilling was performed, the rig cantilever could skid in and out with HP drilling riser suspended without breaking out riser connections.

The base cost reduction had been accomplished by utilizing a jackup rig which daily rate is much lower than floater rigs, and the contribution of the additional features of HP drilling riser and STD combination had further optimized the cost. This experience had brought a major breakthrough in drilling operations in Indonesia and KEI believe that the drilling campaign had been executed successfully with a diligent planning and articulated drilling programs.
Biological Effect Monitoring Benzene at Oil Company, What is New?
Authors: Cahyono Dwi , Tjahjono E. W.
Published: October 2013

Background

Benzene is a proven human carcinogen. Exposure to benzene increase incidence of leukemia. The aim of this study is to determine the chromosome breakage of lymphocyte in benzene exposed worker.

Method and Result

The benzene management in TOTAL E&P INDONESIE conducted by performing identification of benzene sources, air monitoring, personal dose measurement, and biological monitoring.

Benzene sources are identified in the location: flotator, pigging, and oil water treatment. Mostof the benzene air concentration reach above Threshold Limit Value (>1 ppm), some are above 250 ppm. Most of personal exposed monitoring and biologic monitoring is below the maximum standard. Risk management was also performed.

The health surveillance in 115 samples shows: 73 samples (63%) have chromosome breakage (banding), 99 (86%) for non- banding. Variables that are statistically significant (p<0.05) are work locations, positions, SPMA in urine, PPE, Respirator use, Vitamin C intake and tea consumption.

A higher breakage of chromosome numbers 3 & 6 found among workers exposed to benzene compared to non/less exposed.

Main Findings and Policy Implication

The finding of this study is the chromosome (3 & 6) breakage among workers exposed to benzene. Despite well recognized benzene effects (leukemia), other possible implications on health can be different for certain populations as chromosome numbers 3 and 6 are associated with endocrine/metabolic and immunological disorders. This is consistent with fact that more than 40 years operation, no leukemia case detected among the workers in TEPI.

Workers health surveillance shall be continued to detect the possible early effects on endocrine/immune systems. Benzene exposed should be further controlled by management benzene exposure (Regular benzene exposure measurement of air ambient and biological monitoring, engineering control of benzene source), antioxidant consumption and behavior of employees in using proper respirator.
Liquid Carbon Dioxide Flooding in Low Temperature Oil Reservoirs
Authors: Moradi B. , Awang M. , Sabil K. M. , Shoushtari M. A. , Moradi P. , Ajdari H. , Shuker M. T.
Published: October 2013

Carbon dioxide injection in oil reservoirs is one of the main improved oil recovery methods; in addition, it is a useful method for the reduction of carbon dioxide in the atmosphere. Carbon dioxide generally exists in supercritical state in hydrocarbon reservoirs that are usually explored, but the temperature of some shallow reservoirs and reservoirs underlying permafrost is below the critical temperature of carbon dioxide which provides a unique opportunity for liquid carbon dioxide storage and the application of a novel enhanced oil recovery method. During this work, a compositional simulation study is conducted by a commercial compositional reservoir simulator to evaluate performance of the liquid carbon dioxide injection in a low temperature heterogeneous reservoir. The results show the oil recovery factor after 24 years of production, during liquid carbon dioxide injection is 14.79 %, which is 3.90 and 8.59 % higher than the water flooding strategy and natural depletion respectively. It also finds that the huge amount of CO2 is stored in the reservoir. This study further shows that the oil recovery increases by increasing the injection pressure and the injection of the liquid carbon dioxide in bottom of the reservoir.
In-Situ Stress Test Data – Revelation to Optimization of Stimulation Strategy of an Unconventional Reservoir
Authors: Gupta Anish , Chowdhury Manabesh , Mathur Mohit , Ojha Aditya , Shukla Sourabh
Published: October 2013

Characterization of in-situ stress is critical for fracture modeling and developing low permeability reservoirs. An optimum stimulation strategy is required to achieve and sustain the economically viable production from such reservoirs with hydraulic fracturing on the basis of robust formation stress information and modeling.

The Barmer Basin is situated in Western part India in the state of Rajasthan. Though the main prolific reservoir is Fatehgarh Formation, in northern part of the basin the shallower low permeability Barmer Hill (BH) Formation also contains significant hydrocarbon resources. The reservoir is a finely laminated siliceous unit of probable diatomitic origin with high porosity (25- 35%) but low mobility (0.01-0.3 mD/cp). Hydraulic fracturing has been established the key to develop this reservoir.

An integrated formation evaluation was undertaken in Mangala Field to address the uncertainty in the in-situ stress properties of different units of the reservoir. Wireline formations tester’s dual packer module was used to measure the in-situ stress in several zones of the Barmer Hill and shallower Dharvi Dunger formations using the micro-frac technique. The shallower Dharvi Dunger (DD) Formation was also a part of the stress testing to achieve the well integrity and confirming as a frac containment unit for Barmer Hill frac growth.

In-situ stress data was successfully acquired and profiling in the wells X and Y quantified and proved that a significant stress contrast exists among several layers of the BH and DD Formations. This critical information may lead to the revision of the planned hydraulic fracturing design wherein earlier assumption was less stress heterogeneity in different units. The results obtained were used to calibrate and update the frac model by developing an in-house stress correlation to quantify proper frac growth.

This procedure and application can be applied in successful exploitation strategy for other low permeability unconventional reservoirs.
Dynamic Imaging of Fluid Mobility in Low-Permeability Rocks Using High-Resolution Positron Emission Tomography
Authors: Maucec Marko , Dusterhoft Ron , Rickman Richard , Gibson Ron , Buffler Andy , Stankiewicz Maciek , van Heerden Michael
Published: October 2013

Positron emission tomography (PET) continues to have wide-ranging medical application and is based on the detection of gamma radiation emitted from the decay of certain types of radionuclides. Modern PET scanners produce three-dimensional (3D) images of the radiation source, in discrete time steps, using tomography analysis. This paper presents an application of PET for studying fluid mobility in pressurized low-permeability rocks in the presence of natural fractures. This technique uses a high-resolution PET scanner and image reconstruction based on filtered back-projection. Traditional techniques have been limited to pressure measurement of fracture conductivity and effective permeability, but little is understood about the dynamic flow and velocity profiles within the fracture.

The objective of this work was to investigate if it is possible to measure the dynamic (e.g., time-lapse and continuous) distribution of the fluid flow as a function of the overburden stress. PET imaging was applied to the flow of brine solution, which was tagged with 18F-fluorodeoxyglucose (FDG) positron emitting radionuclide, through nonfractured sandstone and naturally fractured shale cores. A special composite container was manufactured to sustain high-pressure conditions and minimize the absorption of emitted gamma rays. The experimental apparatus is described, and it is demonstrated that the 3D images obtained with a grid resolution of 2 *2 *2 mm3 allow clear determination of the fluid flow rate through the core as a function of overburden pressure and time. PET images are direct observations of the radiation source and allow an unambiguous determination of the fluid distribution in the core. The results of this research can be used to validate the numerical modeling of fluid flow through fractured rock matrices, to enable more accurate estimates on the directionality of fractures from the fluid distribution as a function of time, and to obtain more quantitatively sound estimates of fracture connectivity.
Comprehensive Formation Evaluation of HF Carbonate Reservoir by Integrating the Static and Dynamic Parameters
Authors: Zhu Guangya , Wang Xiaodong , Guo Rui
Published: October 2013

This paper presents some new laboratory parameters and a process to describe and characterize the low permeability carbonate reservoir. The objective is to provide a method integrating both static and dynamic data with the physical rock properties for low-permeability reservoirs. Based on the laboratory experiments by using the mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR), relative permeability curves and physical simulation experiments of core samples, the pore microstructure features of low permeability carbonate reservoir and its influence on the formation petrophysics were analyzed. New formation evaluation parameters for low permeability carbonate reservoir are proposed involving mean pore-throat radius, movable oil saturation and threshold pressure gradient. Results of the MICP indicated that there mainly 6 type pore-throat distribution. Good exponentiation interrelationship between permeability and the mean pore- throat radius. Results of core flooding experiments indicated that the pore structure have eminent influence on the threshold pressure gradient. Results indicate that there are good relationship between the movable fluid saturation and the permeability. New parameter had been proposed to identify the fluid mobility such as irreducible water, movable oil and residual oil. Results show that moving oil saturation should be an assessment indicator to water drive oil well. Nonlinear flow would occur and reduce deliverability in low permeability reservoir. Incorporated with petrophysics, mean-pore throat radius, threshold pressure gradient and movable fluid saturation a comprehensive evaluation method has beenestablished. According to this method, reservoirs can be classified into 4 types. Results indicatedthat the new parameters and method presented in this paper would have broad application prospect ingeological selection area techniques and well effective spacing evaluation for the development of low permeability carbonate reservoirs.
Six Zone Intelligent Completion Installation Benefits and Lessons Learned Before Production in Offshore Indonesia
Authors: Jugdaw Sanjay , Mclauchlan Alan , Leith John C. , Dave Rajat
Published: October 2013

Since the late 1990’s, the intelligent completion market has been struggling with the challenge of increasing the number of segmented zonal isolations by minimizing risk and consequently increasing overall production. Risk has been manipulated by restricting the number of zonal segmentations which results in loss of potential zones, non-optimized reservoir drainage due to commingling two or more zones into a single zone impacting reservoir performance.

The obvious benefits of intelligent completions are often not visualized until after deployment; the active management of the reservoir with the aided faculty to monitor reservoir performance through down hole gauges and surface digital infrastructure.

The often overlooked benefits of intelligent completions are the ones that are invaluable during the installation providing seamless operational excellence with the manipulation of the interval control valves (ICV) for the purpose of testing, and to control potential well issues such as fluid loss and well control.

This paper presents a case history from Indonesia in which a six zone intelligent completion was installed inside a single trip multi-zone (six zones) sand control system with complete zonal isolation, control and the ability to measure a total of twelve (12) pressure and temperature points from the subsea well.

This document will highlight the challenges involved in bringing a custom solution to reality in a short time from concept to installation. At the same time it will also demonstrate the benefits brought to the operator when managing fluid loss and maintaining well control through the use of the down hole intelligent completion interval control valves prior to landing the completion.

Deployment challenges, solutions, successes experienced at the well site and the actual performance of the operations will be detailed in the paper.
Using new Technology to Improve "Production Efficiency" and "Lower Operational Risk"
Authors: Mackay Iain , Singh Neil
Published: October 2013

The Oil and Gas industry currently faces some of the greatest challenges in its history; increasing demands to deliver sustainable operational improvements, regulatory scrutiny, crippling maintenance backlogs, poor plan accuracy and below optimum plan attainment results. As stakeholder expectation of operational performance continues to rise, organisations need to have deeper insight into frontline activities, in order to improve.

At the heart of the problem is the complex interaction between the work management business process, asset integrity management (barrier management and impairment) and their impact on overall operational risk. Typically organisations manage the work identification and planning phases of the business process with software systems. However most still use antiquated paper based systems characterised by forms in triplicates or limited standalone electronic systems to manage the work execution phase. These systems provide a limited static view of work risk, no tactical or strategic appreciation of the cumulative work risk arising from planned and emergent work, and virtually no holistic consideration of barrier impairments and the impact of work risk. Finally with no data, no end to end integration and thus no feedback loop it is virtually impossible for these systems to help improve the understanding that drives better decision making and to cultivate asafer, more productive environment

In this whitepaper, we will demonstrate how fully integrated technology systems can be used to intelligently link integral safe work planning and risk management processes to safe work control. In doing so, these systems can provide the means to complete the planning to execution work management business process, safely and sustainably. The data and information collected as a part of routine work completes the feedback loop as it is sent back to the other systems supporting the business process. Plan accuracy and plan attainment are improved as the planners have the actual details of what it took to do the job, improving the inputs to the plan the next time the work orders are executed. Contractor wait time can be reduced dramatically and frontline supervisors have the tools to optimise of the safe work plan to reduce operational risk and operational inefficiencies.

By utilising new technology for the work management business process, senior management can, for the first time better understand and balance the relationship between delivering performance and operational risk.