bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fundamental Investigation of Mechanical Properties of Additives and Class H Cement Under Downhole Conditions
Authors: Li Li , Boncan Virgilio C. , Brandl Andreas , Jordan Andrew K. 
Published: October 2015

Abstract
The foremost function of primary cementing is to achieve zonal isolation and ensure long-term cement integrity during the lifetime of the well. Current advanced drilling and cementing technologies enable the production of oil and gas in more complex and challenging conditions such as deep wells and unconventional wells either onshore or offshore. Understanding the mechanical performance of cement sheath under downhole conditions, therefore, is crucial for successful cementing operations. Unfortunately, most published mechanical data were still limited to the compressive and tensile strengths determined at ambient condition as well as Young's modulus. The result for tensile strength varies greatly due to the lack of API standard tensile strength testing.
The purpose of this study is to evaluate the additive-additive interaction on cement mechanical properties. Individual additives and their combinations were mixed with class H cement at a density of 16 ppg and cured under elevated temperature and pressure. The mechanical properties tested at ambient and curing conditions include compressive, tensile and yield strength, Young's modulus, and Poisson's ratio. The cement mechanical performances measured at curing conditions, especially the tensile strength, were different from the results obtained at ambient conditions. The elasticity of cement was improved by fiber and polymeric additives tested in this work. This study provides comprehensive experimental data on how the slurry formulation, chemical characteristics of the additives, and additive-additive interactions can affect cement mechanical properties. This study also gives insights into the correlations among various mechanical properties, and the key parameters that could determine cement elasticity. The results can be used as direct guidance for future field applications.
Unlocking Oil Potential in Mature Field Using Linear Rod Pump
Authors: Putro Wiarto Aryoso , Edy I Ketut , Saputra Reza , Anantokusumo Ferry 
Published: October 2015

Abstract
Mutiara is a mature field located in the onshore part of East Kalimantan which has been on production for over 30 years. The field is dominated by gas reservoirs with a much lower presence of oil reservoirs. Production mechanisms range from natural depletion to weak and strong water drive, particularly in some of the shallow areas. High decline rates are very common, which results in a very dynamic and challenging environment. The main artificial lift used in this field is gas lift. However, this method is not efficient for depleted or high water cut wells. Another issue is oil wells which located in remote areas which need high investment for surface facilities including gas lift line network and sufficient pressure to lift the oil up to the surface. Therefore, more and more wells will be idle without implementation of other artificial lift systems techniques.
Several downhole pumping types have been assessed to tackle these issues such as Electric Submersible Pump (ESP), Progressive Cavity Pump (PCP), and Linear Rod Pump (LRP). Considering hilly swampy conditions of the field that requires more compact type of surface unit and flexible to match displacement rate to well capability as well declines. It is then decided to use LRP to unlock oil potential in idle wells.
The first installation of LRP was on September 2014 in X-1 well, this well is the first well drilled in 1982. This installation succeeds on bringing back the well on production. The application of LRP provides opportunity to unlock oil potential from idle wells in this mature area thus maximizing reserve by gaining a few more hundreds barrels of oil per day during the first year.
A New-Simple-Effective Analytical Approach to Determine Intermittent Gas Lif Parameters
Authors: Tasmi Tasmi , Rahmawati S. D. , Sukarno P. , Siregar S. , Soewono E. 
Published: October 2015

Abstract
Intermittent gas lift is commonly known as one of artificial lift technique that is implemented into wells with low bottom-hole pressure. The injection process will be in cycles with spesisified period. Previously, intermittent gas lift is modeled using nodal analysis method, which is intersection between inflow performance relationship (IPR) and tubing performance relationship (TPR) and mechanistic method. Both solutions required a hard-working numerical approach to solve the model. In this paper, a new-simple-effective analytical approach is introduced to solve a set of equations that was derived from Transport Reynolds Theorem. The work is slightly different from the Liao and Bordalo model. A complex equation that represents movement of the gas-column, the slug, and the film from surface to sub-surface is presented. Gas column is formed during the injection time and the injected gas will push the oil to the surface. The dynamics of the gas column greatly affect the success of the process of oil production with gas injection method intermittently. The gas-column pressure, surface injection pressure and rate, gas column density, and surface gas injection density are successfully obtained using this approach. The gas-column pressure in the tubing is strongly influenced by the surface gas injection rate. By controlling the surface gas injection rate then the column-gas pressure in the tubing will be stable. The stable gas-column pressure leads to the stable oil production. This research is genuinely believed to be the first analytical approach of determining intermittent gas lift parameters. The results are give huge advantageous and applicable either for the educational as well as industrial purposes.
Improve the Performance of CO2-based Fracturing Fluid by Introducing both Amphiphilic Copolymer and Nano-composite Fiber
Authors: ZHANG Jin , MENG* Siwei , LIU He , LV Xinrun , ZHANG Rong , YU Baihui 
Published: October 2015

Abstract
Liquid CO2 fracturing is an outstanding stimulation treatment for unconventional reservoirs, such as coal-bed methane reservoir and shale gas reservoir. However, the viscosity of liquid CO2 is extremely low, only 0.03 ~ 0.10 cp under reservoir conditions, resulting a very poor proppant-carrying capacity. Meanwhile, liquid CO2 is a kind of Newtonian fluid, its friction is very large. All these properties greatly reduce the stimulation results.
A novel copolymer composed of CO2-philic fluoride and CO2-phobic partly sulfonated styrene is synthesized. Computer simulations show that these copolymers can create the macromolecular structures via non-covalent association, thus will greatly thicken CO2. Experimental tests showed that this copolymer can increase the solution viscosity 100-fold relative to neat carbon dioxide at 333K and 28 Mpa with a concentration of 1 wt %.
A new kind of nano-composite fiber is also introduced to further improve the performance of the CO2-based fracturing fluid. This nano-composite fiber is synthetized by introducing nano-particles in the conventional polyester fiber. A novel CO2-based fracturing fluid with both the amphiphilic copolymer and the nano-composite fiber added was then developed. A series of evaluation tests were performed in laboratory. The results showed that this fiber can disperse easily in the fluid and an addition of very small amount (0.5%) can enhance the proppant-carrying capacity drastically. At 263K and 28MPa, friction can be cut by 17% via adding 0.5% nano-composite fiber under the shear rate of 5000s−1. Meanwhile, nano-composite fiber can prevent backflow of proppant effectively. Leak-off of fluid can also be mitigated significantly.
The addition of both the amphiphilic copolymers and the nano-composite fibers can significantly improve the performance of liquid CO2 fracturing fluid, thus may greatly enhance the stimulation results of the liquid CO2 fracturing.
A Novel Dynamic Model to Simulate Waterflood Induced Fractures in Low Permeability Reservoirs
Authors: Fan Tianyi , Wu Shuhong , Zhang Xiaozhou , Wang Baohua , Li Qiaoyun , Li Xiaobo , Li Hua 
Published: October 2015

Abstract
In China, a number of low permeability reservoirs have few fractures at the first stage of development, such as Ansai Oilfield in Changqing and Xinmin Oilfield in Jilin. However, they show fracture influenced characteristics gradually with the processing of waterflood later on. It could be attributed to the waterflood induced dynamic fractures generated during the waterflood process. The presence of the dynamic fractures could lead to volcanic water flooding and directly impact the effectiveness of reservoir development.
Based on abundant field data and laboratory data, a new dynamic model to simulate waterflood induced fractures in low permeability reservoirs is established. Compared with the existing models of dynamic fracture, this new model describes the dynamic variation of morphology and permeability of the fractures changing with the formation pressure simultaneously. Thus, this model gives higher reservoir simulation accuracy.
In this thesis, the influences of dynamic fractures on water cut of production well, the water injection timing and the water injection pressure are discussed respectively. Simulation results show that dynamic fractures significantly influence the development effects of low permeability reservoirs.
This model can predict the development results of low permeability reservoirs with dynamic fractures. It gives guidance to adjust the strategy of injection wells and production wells in time. Thus, oil recovery and economic benefits could be increased.
Increasing Brown Oil Field Recovery Factor by Integrated Subsurface Review, Drilling & Workover Operation, and Surface Facility Reconfiguration – Case Study: Rama E Platform Reactivation
Authors: Afi Futiha Nur , Dondo Maximilian , Ratna Nova , Aji Wahyu Seno , Noviansyah M.. , Nurdin Syaiful , Maulana Anton , Hadi Wiryono , Adi Frans , Pentury Nootje , Setiyaka Ary , Pasaribu Martua , Ramadhi Priya , Gunawan Hendrata 
Published: October 2015

Abstract
Deal with brown oil field with runlife of the production more than 35 years has many challenges. Pressure depletion was one of the main concerns of maintaining survival of the field. From the geological aspect, reservoir which produced from limestone was also have many challenges, especially for heterogeneity of the reservoir. Both problems were faced in Rama field which impact the low recovery factor of this brown limestone field. Some approaches was held to increase oil recovery of this field, integrated sub surface review was done aggressively to bring some concept and followed up by some efforts from drilling, workover also surface facility.
Rama field was developed in 1975 with the initial production was about 20,000 BOPD. As of June 2009, Rama field has been producing more than 137 MMBO with production ± 4,000 BOPD mainly from Upper Baturaja. A waterflood project was held in the field from 1982 until 1991 where a large amount of sea water had been injected into Baturaja formation. As the result, the reservoir pressure increased and maintained from 700 psi into 950 psi during the water flood period. However, early water breakthrough was occurred as well and got the water cut jumped into more than 90% from initially 60%. In some wells the water cut could be as high as 99%. Due to its bad impact on the oil production the water flood project was suspended in 1991. Ten years later an oil re-saturation phenomenon has been observed from some wells produce from Upper Baturaja with water cut in the range of 50–90%. The oil production rate from Upper Baturaja was 3,000 BOPD with 85% - 90% water cut. In early 2009 two infill well was drilled and one well was reactivated and gave good indication of decreasing water cut
Rama E wells are among the wells that got bad impact from massive waterflood due to water cut increase, and one by one those wells are abandoned. The platform itself has been abandoned since 1999. Regarding good result of two infill and one reactivation wells, it was proposed to reactivate Rama E platform by modification of Rama-E platform include refurbishment of existing platform, installation of mezzanine deck, Power Control Room, iso-transformer, production process piping and equipment. Reactivation of the wells themselves would be done using jack up rig and snubbing unit.
The objective of this project is to add oil reserves and production with sufficient cost by doing reactivation abandoned platform without drilling new wells.The recovery factor by June 2009 from Upper Baturaja is estimated 14% (OOIP ≈ 505 MMBO). By reactivation of five wells in Rama E, reserve increase up to 631 MBO (2011), it was increase recovery factor significantly.
Operating a Philosophy - Shale Gas Efficient Development in China
Authors: Liu He , Yan Jianwen , Yang Qinghai 
Published: October 2015

Abstract
The Shale Gas Revolution began to have a significant impact on global supply and demand of natural gas, also the price trend of natural gas has been greatly affected. This phenomenon aroused concerns among natural gas producers and consumers. China has abundant shale gas resources, but the development scale is small while facing problems including weak exploration and evaluation basis, overlapping royalties, complex terrestrial environment, lack of technical practices and accumulation, inadequate management and regulatory mechanisms, etc. To overcome these challenges for large-scale shale gas development, we believe that shale gas development is not only a single technical problem, but a systematic engineering demanding multidisciplinary research that will be bound to spread to humans, nature and society. Therefore, to ensure the healthy development of China's shale gas, it is required to coordinate global and local relationships, engineering and community relations, and to break up the conflicts between engineering and nature, engineering and economy, as well as engineering and society.
A Novel Calculation Method for HPHT Deep Gas Well Control
Authors: Elgassier Mokhtar M. 
Published: October 2015

Abstract
When a wellbore is completely or partially filled with gas and work over or drilling operations are to be carried out on the well, it is necessary to bleed off the gas and replace it with liquid or mud to maintain well control.
The replacement of the gas in the wellbore by liquid is commonly done in small stages with gas being released after each stage. This procedure usually requires a long time and could lead to adverse consequences.
The method proposed in this paper will enable engineers to determine in advance the exact volumes of liquid necessary to pump into the well and the exact volumes of gas to bleed off after each injection so that the bottomhole pressure always stays above the formation pressure but below its fracturing pressure. The method takes into account the integrated pressure calculation due to a real gas column in the wellbore. Thus, the variation of the gas deviation factor with pressure and temperature of the gas in the wellbore is taken into account. The results obtained assuming real gas behavior vs. ideal gas can be significantly different in the number of stages, volumes calculated and pressures especially for deep high pressure and temperature wells. Two calculation procedures for the volumes and pressures are presented in the paper. These procedures are outlined step by step in the paper. The procedures are fast and eliminate the need for unnecessarily small injected liquid volumes and remove the element of guessing and the danger of unforeseen consequences.
Effects of Adsorption and Confinement on Shale Gas Production Behavior
Authors: Zhang K. , Wang M. , Liu Q. , Wu K. , Yu L. , Zhang J. , Chen S. 
Published: October 2015

Abstract
Shale gas becomes an important natural gas supplier in recent years. The technologies including horizontal wells and hydraulic fracturing drive the booming of shale gas industry. Gas in shale reservoirs is stored as free gas in both mineral pores and natural fractures, as well as absorbed gas on pores surface. The effect of gas adsorption is generally ignored in conventional reservoirs. However, the absorbed gas has to be taken into consideration for shale gas production because of its huge amount in nanoscale porous media. The smaller the pore throat radius, the more significant is the effect of confinement. Therefore, production behavior can be altered by the effects of adsorption and confinement in shale gas reservoirs. On the basis of Montney shale gas reservoir modeling, effects of adsorption and confinement on shale gas production behavior are investigated in this paper. Results show that total gas production increases with the consideration of adsorption and confinement effects. As gas density and viscosity decreases prior to condensation occur with the effect of confinement caused by nanoscale pore throat, incremental of density difference between free gas and absorbed gas will delay the production of absorbed gas. Moreover, the difference between the amount of free gas produced and absorbed gas produced become larger with the effect of confinement during reservoir depletion.
Application of Plume Cooling Technology to Solve a GTG Impingement Problem - A Case Study
Authors: Thompson J. , Crampton R. 
Published: October 2015

Abstract
Exhaust plumes from generators, pumps, and compressors aboard offshore platforms pose a hazard to crew and equipment. Mitigation for exhaust plume impingement has traditionally been achieved by locating the exhaust uptake away from sensitive areas of the platform, either by use of long horizontal duct runs, a very tall exhaust stack (&gt; 20m), or some combination of the two. These solutions result in an exhaust system that is complicated to design and that adds a lot of weight to the platform. A more practical and weight efficient alternative exists: plume cooling.
Plume cooling technology has been in use for more than 40 years on military ships for the purpose of infrared signature suppression, and for the protection of sensitive weapons and communications systems that would otherwise be damaged by hot impinging exhaust gases. The operating principles of a plume cooler for application to the offshore oil industry are the same as for a military ship. The use of a plume cooler allows for a more compact and lightweight exhaust, but surprisingly this technology has only started being applied on offshore platforms in the past couple of years.
The authors of this paper have more than 28 years of combined experience in the design and manufacture of plume coolers for diesel and gas turbine engines. In this paper the authors present a typical plume impingement problem aboard an offshore platform: an LM2500 gas turbine generator (GTG) that is located centrally in close proximity to the helipad, derrick and deck crane. Using the tools they have developed for plume dispersion analyses on military ships, the authors present the predicted impingement impact of the baseline exhaust on areas of interest (AOI) on the platform as well as the benefit of applying plume cooling. A comparison is also provided between the plume cooling solution and the traditional solution of raising the exhaust stack height, with weight being a main point of comparison.
A Comparison Study of Utilizing Optimization Algorithms and Fuzzy Logic for Candidate-Well Selection
Authors: Xiao Yong , Guo Jianchun , Songgen Songgen 
Published: October 2015

Abstract
It is widely acknowledged that 80% of oil and gas reservoirs in the word are capable of producing at commercial rate only when it is hydraulically fractured, but a good reservoir quality of itself is the resource of production after fractured. Therefore, it is evident that adoption of this technology needs strenuously considerable efforts in candidate-well selection. This paper presents a novel approach of candidate-well selection by combining fuzzy logic, gaussian membership function, multi-level grey correlation analysis, imperialist competitive algorithms with artificial neural networks, fuzzy C-means clustering and C4.5 decision tree in one of heterogeneous gas reservoirs in China. Firstly, the model of artificial neural networks, fuzzy C-means clustering and C4.5 decision are introduced. Then, in comparison with the calculation processes and results, a detailed gas reservoir case is employed to prove the differences among them. Case study verifies that not only the parameters of membership degree and weight can be obtained by fuzzy logic, but also more accurate prediction of gas production and results of candidate-well selection.
Revealing the Uncertainty of Heterogeneities in Fractured Basement: A Case Study from the South Malay Basin Offshore Peninsular, Malaysia
Authors: Gaafar Gamal Ragab , Najm Ehab , Ming Wu Ivan Zhia 
Published: October 2015

Abstract
Fractured basement reservoirs represent more than 20% of the world's oil and gas reserves. Because of their heterogeneity and complex, unconventional natures, the process of mapping the reservoir properties presents a monumental task. The identification of the high productivity zones in basement reservoirs presents a major challenge because of the drastic vertical and temporal variation in porosity and permeability.
Reservoir characterization in terms of rock-forming minerals, multipore system analyses, hydrocarbon typing and quantification, and textural variations can be performed by combining quad-combo, elemental spectroscopy, and resistivity-imaging measurements, regardless of the conveyance technique, in an integrated workflow.
Because fractures play a major role in hydrocarbon production, rapid reservoir decline, and undesirable fluids breakthrough, fracture description is crucial. Aside from conventional techniques to quantify matrix porosity and permeability, a workflow has been designed to provide additional unconventional techniques for multipore system analyses using high-resolution resistivity imaging. With one technique, the resistivity image is sculptured using an object-oriented filter that produces fracture density, aperture, and porosity. The other technique is based on a transformation of image conductivity to porosity that is classified into a matrix and secondary pores to estimate their contribution to permeability.
The multipore system analysis is then used to determine the cementation exponent parameter needed for hydrocarbon quantification. Finally, critically stressed fractures are identified, using geomechanical analyses, to determine the production-contributing fractured zones.
Although the technique/workflow used is relatively new and uncommon for data acquired while drilling, its results successfully met the objectives of the study with quality deliverables.
This paper presents a basement reservoir characterization study with a discussion of the technologies used in the workflow, study results, conclusions, and recommendations for future work. Data used in this work were obtained from a well in Malacca, Malaysia.