bluuebunny/crossref_metadata_2025_split huggingface dataset:
QC of the Reservoir Model Using Seismic, Well Logging and Petrophysical Data
Authors: He Weisheng , Ling Yun , Guo Xiangyu 
Published: May 2016

Abstract
For the oil fields in the mature stage, it is most important to find the remaining oil in the reservoir. A typical method to predict the remaining oil is fluid flow simulation based on the geological model generated with all the available data. The agreement between the reservoir simulation model and the production data is usually used to evaluate the quality of the simulation model. Reservoir engineers often find that more than one simulation model could match production data, which is due to the limitation of the production data, only available at the well location. However, the seismic data are available in 3D. A method of quality control of the reservoir model using 3D seismic, well logging and petrophysical data is proposed in this paper. The proposed method is applied to a pilot test in a heavy oilfield. Using the well logging data and seismic horizons in the study area, a geologic model was generated and upscaled to a simulation model. With this model, reservoir simulation was run to simulate the reservoir changes over the time. Using the petrophysical data, the synthetic seismic data of reservoir model were calculated. And then the synthetic seismic data were compared with the observed seismic to evaluate the reliability of the reservoir model. The application shows that the introduced method can be used to quantitatively evaluate the reservoir model and its outcome can also aid us to update the reservoir model. The updated model is proven to be more reasonable.
Derisking of Unconventional Gas Opportunities: Application of Basin Modelling
Authors: Keym Matthias , Dieckmann Volker , Meuric Olivier , Idiz Erdem 
Published: May 2016

Abstract
Unconventional Liquid Rich Shale (LRS) and shale gas (SG) plays are self-charged continuous systems relying on their indigenous organic matter as the source of hydrocarbons. The residual pore space of fine-grained organic rich sediments themselves or similarly tight deposits in their close vicinity act as the reservoirs. Pressure (P) and temperature (T) can significantly increase during burial of the sediments and can likewise undergo a substantial instant P but time-deferred T decrease during erosion and uplift. These changes in P and T strongly influence the phase behaviour of the generated and trapped hydrocarbons (HC), thereby affecting the retention capacity of the source rock, the HC flow properties, potential migration routes, and the predicted HC volumes initially in place (GIIP/OIIP). Shell's integrated Cauldron Shale Gas Simulator calculates resource density on a regional to basin scale, typically during the opportunity identification and screening phase of a project. Informed decision-making in exploring for unconventional opportunities relies on the integration of all available (i.e., sometimes scarce) data and their associated uncertainties for basin scale physical elements and processes into a working geologic model.
Strain Based Design and Material Selection Technology for Thermal well Casing
Authors: Lihong Han , Jianjun Wang , Hang Wang , Changyi Qin , Yaorong Feng , Bin Xie , Xuelu Zhang , Zhihua Tian 
Published: May 2016

Abstract
Field investigation and failure analysis on casing damage were conducted for cyclic steam stimulation thermal wells in Xinjiang oil-field of China. Evaluation demonstrated that stress-based casing design only meet the requirements of drilling and completing operation, but could not accommodate sufficient security for cyclic thermal production. Although casing failure seldom appeared during drilling and completing, lots of its failures happened within the following production stage. These results indicated that the service environment during this production is the dominant factor affecting casing design and material selection.
Failure analysis displayed that there are several typical modes, including deformation, necking, shear, crack and connection parting. These typical modes revealed that those casing experienced obvious plastic deformation during production. Accordingly, strain-based design is proposed in which characteristics of deformation behaviors are taken into account, such as plastic deformation, hardening, creep, stress relaxation, bauschinger effect and strain fatigue limit. Two criterions were determined for this design according to plastic capacity and strain fatigue limit of casing material, respectively. Moreover, one of these criterions had been verified through 8 wells experiments after three thermal cycles.
Strain-based design aims to present sufficient axial plasticity capacity beyond elastic limit, before ultimate necking and tensile fracture. It is necessary to consider attached measures for integrity of thermal wells. For thread connection, sufficient sealability is recommended to prevent steam leakage, otherwise which could greatly promote shale's expanding and then result in shear failure in casing. As for the pipe ends, external upset or additional hardening process is suggested to apply to maintain the integrity of thread connection area.
Prediction and Reduction of Perforating Gunshock Loads
Authors: Baumann Carlos , Barnard Keith , Anbao Lu , Williams Harvey , Fuxiang Zhang , Xiangtong Yang , Jianxin Peng 
Published: May 2016

Abstract
Most wells and particularly high-pressure wells are susceptible to gunshock damage when they are perforated with inappropriate gun systems and/or under suboptimal conditions. This paper presents a simulation methodology to predict gunshock loads for tubing-conveyed and wireline-conveyed perforating jobs.
When planning perforating jobs in high-pressure wells, engineers strive to minimize the risk of equipment damage due to gunshock loads. The methodology described here helps engineers to identify perforating jobs with significant risk of gunshock related damaged, such as bent tubing and unset or otherwise damaged packers. When predicted gunshock loads are larger than the admissible loads, changes to the perforating equipment or job execution parameters are sought to reduce gunshock loads. This methodology enables completion engineers to evaluate the sensitivity of gunshock loads to changes in gun type, charge type, shot density and distribution, tubing size and length, number of shock absorbers, rathole length, and placement/setting of packers, among others.
Fast gauge pressure data from perforating jobs shows that when model specifications are representative of the actual perforating jobs, the predicted wellbore pressure transients are accurate both in magnitude and time. Peak sustained pressure amplitudes at the gauges are on average within 10% of simulated values.
With the methodology presented in this paper, engineers can evaluate perforating job designs in a short time, and they can optimize perforating jobs by reducing gunshock loads and equipment costs. The ability to predict and reduce gunshock loads and its associated damage is very important because of the high cost associated with most wells, particularly high-pressure wells. With the software presented in this paper engineers can optimize well perforating designs by minimizing the risk of gunshock related damage and the associated rig time losses.
New Truck Vibrator for VSP Surveys, Extending the Frequency Bandwidth
Authors: Tulett J.R. , Dean T. , Armstrong P.N. , Lane D. 
Published: May 2016

Abstract
On land, the preferred seismic energy source for Vertical Seismic Profile (VSP) surveys is the seismic vibrator, a special vehicle mounted, mobile energy source. Seismic vibrators come in a variety of shapes and sizes, with truck-mounted vibrators the most common vehicle type during the early years of vibroseis surveys.
Truck-mounted vibrators are particularly useful for VSP surveys because the vehicle can be driven directly to the well site, but over the years the surface seismic industry has converted to buggy vibrators due to the buggy's excellent mobility in off-road terrains. This has left a gap in development of truck-mounted vibrators.
With petroleum exploration occurring in deeper wells, more complex sub-surface formations, and with steadily higher expectations for the results of VSP operations, there is a need for higher amplitude, and wider bandwidth seismic vibrators to provide critical geophysical information of petroleum reservoirs.
Overmature Shale Gas Storage Capacity Evaluation
Authors: Tian Hua , Zhang Shuichang , Liu Shaobo , Chen Jianping 
Published: May 2016

Abstract
Shale gas is generally believed to have been stored in forms of free compressed gas in open pores and cracks, as adsorbed gas on the surfaces of kerogen or clay minerals and as diffused gas stored within the solid organic matter (Bowker, 2007, Sondergeld et al., 2010). The nano-pores[1], which have a great effect on the shale gas occurrences, are the predominant pore type in the Barnett mudstones (Loucks et al., 2009). Therefore, it is important to understand the pore network and shale gas storage mechanism. This study aims to reveal the key affecting factors of pore development, and establish a shale gas prospect evaluation model as a function of pressure and temperature of overmature shale.
A set of outcrop and downhole samples were selected from the Sichuan marine basin and the Bohai bay lacustrine basin of China, and an immature shale outcrop sample from the Fushun Basin, northeastern China was used for pyrolysis experiment. A series of nano-pore description methods, such as FESEM, CO2 low pressure isotherm analysis (D-R method), N2 low pressure isotherm analysis (BET theory), Hg porosimetry were used to observe pore size, morphology, and abundance in gas shale. Methane adsorption capacity was measured use the isotherm adsorption system from TerraTek.
The N2 gas adsorption at low temperature and pressure (BET theory) (Bustin et al., 2008) showed that, with increasing pyrolysis temperature, the surface areas increase from 354 m2/kg (sample FS-300) to 3,102 m2/kg (sample FS-600) (Table 1), and pore volumes increase from 0. 6448 cc/kg (sample FS-300) to 10.89 cc/kg (sample FS-600) (Table 1; Figure 1), indicating that additional pores had developed in the solid products during the progressive pyrolysis. Pore volumes increase as the pyrolysis temperature increases, indicating that the pore volume in the organic matter can increase significantly during shale maturation (Table 1).
Scanning Electron Microscopic (SEM) observation of the pyrolysis residues indicates that with increasing pyrolysis temperature, the pores in the shale become more abundant. The sample of low-pyrolysis temperature contains fewer and relatively small pores compared with that of high- pyrolysis temperature (Figure 2). Sample "a", which was pyrolysed at 300 ?, corresponds to the low end of the hydrocarbon generation window. There are few micro-pores in the organic matter with the surface of the organic matter being relatively flat. The pore networks in Sample "b" which was pyrolysed at a higher temperature of 550? contains abundant pores developed in the organic matter, which are in sharp contrast with that in Sample "a". This is consistent with the intraparticle organic nano-pores interpreted to be of thermal maturation origin by Loucks et al. (2009) in the Barnett mudstones, where the nanopores most commonly have irregular, bubblelike, elliptical cross sections and range between 5 and 750 nm.
ALARP Demonstration in UCG Trial Production Operations (TPO) Facility Design
Authors: Kian-Hua Sim , Su-Fook Lo , Yun-Chung Liaw 
Published: May 2016

Abstract
This paper presents various techniques/ tools used to demonstrate the major Health, Safety and Environment (HSE) risks involved in the tight gas appraisal program, especially in designing the surface facility for the Trial Production Operation (TPO), has been reduced to As Low As Reasonably Practicable (ALARP). In the challenging environment of central Sichuan basin i.e. local hilly terrain and densely populated farm land, the paper looks at the local requirement and importance of the analysis right from the design phase for a safe and efficient operation of the TPO facility. The techniques covered include Hazard Identification (HAZID) Study, Hazard and Operability Study (HAZOP), Safety Integrity Level (SIL)/Instrumented Protective Function (IPF) study, Fire and Explosive Risk Analysis (FERA) and Fire Protection Analysis (FIREPRAN) study.
The paper covers the documentation of ALARP demonstration into a Design HSE Case. Major Accidents Hazards (MAH) in the TPO facility are identified using the Risk Assessment Matrix (RAM). A systematic and structured Hazards and Effects Management Process (HEMP) is applied in the design of the TPO facility and the risks associated with MAHs are actively and systematically reduced to ALARP. The effectiveness of all barriers and controls for each MAH are evaluated and complied with the set criteria (Bow-tie assessment). If the HEMP assessment determines that a barrier or risk management of a MAH is only partially effective, further remedial action and effort is done to close the gap. Besides, Safety Critical Elements (SCE) and their performance standards are identified and developed as a key input to the Asset Integrity Process Safety Management (AIPSM) in the operations phase.
Finally, the TPO facility design on a plot size of 70m x 70m pad was accepted for construction and trial production. Further improvement study and optimization has been ongoing including taking other unconventional gas (UCG) best practices and learning into the development planning.
Cave System Analysis - An Effective Approach to Predict Hydrocarbons in Cavernous Carbonate Reservoir
Authors: Luo Chunshu , Xue Fangjian , Deng Xinglang , Mao Qing , Yang Pin , Zeng Rui 
Published: May 2016

Summary
Paleo krast caves, even deeply buried over 5000 meters, are important exploration targets in Tarim Basin west China. In seismic, large caves could be well observed as strong amplitude anomalies and are characterized as "string of beads" in legacy seismic data. They have dominated the production and reservers of the Ordovician carbonate reservoirs. Successful drilling on these targets quite depends on reliable prediction of fluid types in these karst caves. But seismic hydrocarbon detection has a high uncertainty due to the high variation in cave geometry and the low seismic resolution in deeply-buried carbonate. To improve drilling success rate, cave-system analysis approach was developed in our study as an effective approach to predict hydrocarbons in cavernous carbonate reservoir. Hundreds of paleo-caves have been seismically interpreted. Based on extending tendency of individual cave interpretation, the connections are delineated between caves forming multi-level and multi-branch cave systems through study area. These complex cave systems could be analog to the Mammoth Cave. This analog suggests that most caves in study area were connected during their development time. They are now much less connected due to sediment infilling and collapsing. Within the cave systems, the cave entrances, exits, collapses and relative high points of the cave systems are identified to provide the underpinnings for predicting cave fillings and fluid types, with the support from detailed structural mapping, paleo-topography study, production performance diagnosis, and seismic inversion/ attribute evaluation. Several hundreds of oil-bearing caves are predicted within the study area, providing the main basis for drilling plan. New drilling has led to several high productive wells after two year's unsuccessful drilling in study area.
Investigate the Distribution of Conglomerate Masses and Build the Velocity Model with Integrated Gravity, Magnetic, Electromagnetic and Seismic Data: An Example from Kuche Depression, China
Authors: Dechun Li , Zhi Zhao , Zuzhi Hu , Shujiang Yang , Haiying Liu 
Published: May 2016

Summary
Conglomerate masses, which widely developed in the piedmont area of Kuche Depression, Northwestern China, seriously affect the seismic structure imaging and limit the seismic interpretation precision. As a result, in a deep reservoir well in the area, the error between the predicted reservoir depth and the real one even is up to about 1000 m. It impedes the progress of hydrocarbon development in the depression.
Gravity, magnetic and electromagnetic (EM) responses, especially EM data, are sensitive to the existence of conglomerate masses. An integrated 3D survey including gravity, magnetic and EM methods is conducted in Kuche Depression. All available geophysical data are jointed together and interpreted on an integrated interpretation platform GeoEast®. With the inverted 3D resistivity data we describe the spatial distribution of lithology and with the seismic data we give a believable structural frame interpretation. Joining the two kinds of data as well as drilling data and outcrops information, the distribution of conglomerate masses and their litholohy and lithofacies are comprehensively predicted. Subsequently, we conduct the joint inversion of gravity, magnetic, EM and seismic data and get the structural model of the intermediate and the shallow layers with which we can describe the distribution of conglomerate masses. The work improves the precision of the deep structural trap prediction. Three wells drilled subsequently shows that the maximum error between the predicted gross thickness of conglomerate masses and the real figure is only 3%. The velocity model is also built and used in the subsequent pre-stacking depth migration. It effectively helps limiting the interpretation error which results from the high-velocity horizons. The statistics of drilling data in the area shows that the general misfit of the predicted structure depth decreases from the original about 300 to 1,000 m to the present 30 to 120 m.
After the project, a complete joint interpretation system integrating gravity, magnetic, EM and seismic data is released. The system makes the interpretation of multiple geophysical data changing from the traditionally qualitative comparison job to the presently accurate description based on the multiple geophysical data. The quantitative data output from the platform can be used to build velocity model.
Hydrocarbon Accumulation Process and Exploration Potential of Shizigou-Yingdong Area, Western Qaidam Basin
Authors: Qingyang Meng , Shihu Fang , Yan Chen , Shuiwei Guan , Lili Gui , Li Yuan 
Published: May 2016

Abstract
In recent years, with the successful drilling of Sha37 and Sha 40 wells and discovery of Yingdong No.1 oil field, great breakthrough had been achieved in Shizigou-Yingdong area. And hydrocarbon exploration in Shizigou-Yindong tectonic belt is also blooming. However, contrast with the great achievement in exploration, research on hydrocarbon accumulation process is still weak and exploraiton potential is not clear. In this paper, several advanced methods are adopted to research the hydrocarbon process including QGF and QGF-E analysis on core sample, TSF analysis on oil sample and laser confocal scanning on component analysis of hydrocarbon inclusion. The results of analysis on hydrocarbon inclusion and oil sample by new methods showed that there were mainly two stages (N21 and N23-Q) of hydrocarbon accumulation in this area. Early hydrocarbon charging is mainly low maturity oil and latest charging is high maturity oil and gas. Meanwhile, new concept and dynamic model of structure evolution in western Qaidam baisn demonstrated that the inverse "S" shape structure were formed controlled by Alyn Tagh and East Kunlun strike slip fault. Structure of Shizigou-Yingdong area were first formed in the west and developed eastward. Hydrocarbon accumulation are mainly controlled by regional fault and preservation conditions. The footwall of fault and the eastern part of Yingdong tectonic belt are favorable for hydrocarbon accmulation. The new understanding on hydrocarbon accumulation process and favorable enrichment prediction has great significance to the further exploration and well deployments.

Introduction
Shizigou-Yingdong area located in the western Qaidam basin, where several oil fields including Gasikule, Youshashan, Shizigou and Wunan had been discovered before 2000(Fig.1). There were not big oil or gas fields discovered in the last decade until Yingdong oil field was discovered in the year of 2010. Yingdong oil field is not only one of the biggest discoveries of CNPC, but also one of the richest oil fields in China. In order to research the hydrocarbon accumulation process and exploration potential in this area, large amount of core and oil samples of Yingdong area and adjacent oil fields were collected and analyzed in our laboratory. After observation and datailed analysis of oil/gas inclusion in reservoir core sample, conventional geochemistry analysis of oil samples, dynamic analysis of tectonic movement, formation and evolution of Shizigou-Yingdong tectonic belt, the two stages of hydrocarbon charging history and accumulation process is identified.
Responsible Unconventional Gas Operating Principles in Practice, Sichuan, China
Authors: Cortis Anthony , Zheng Gary , Castle Martin , Jianghong Wang , Feizhou Guo , Westley Karen 
Published: May 2016

Abstract
Shell has published a set of five aspirational global onshore tight sand/shale oil and gas operating principles that provide a framework for protecting water, air, wildlife and the communities in which we operate. We design our activities using state-of-the-art technology and innovative approaches that make the most sense for local conditions. This paper outlines Shell's implementation of these principles in the assessment and development of a Basin Centred Gas play in partnership with PetroChina in a block in Sichuan Basin, China. The 4,106 km2 block lies in the heart of the Sichuan basin, sometimes referred to as the "bread-basket" of China. The area is intensively farmed and is characterized by very hilly topography with problematic access. Population densities are 500–600 people per km2. The partners are executing a 3-year, 21-well appraisal program designed to evaluate the gas potential and commerciality of the block. A successful Development stemming from this appraisal would allow for an extended production period under the auspices of a PSC. Hundreds, if not thousands of wells, could ultimately be drilled. Operating presents unique challenges from a surface perspective because of the potential impact of our operations on local communities. In accordance with the onshore operating principles, Shell China has developed and implemented a number of operating methodologies that ensure we operate our wells and facilities safely, minimize the footprint of our operations, ensure water and air quality and properly engage with local communities. These methodologies, challenges, success factors and future plans to expand them and further mitigate impacts are discussed in detail.