Deendayal P.,Petroleum University
Society of Petroleum Engineers - SPE Annual Caspian Technical Conference and Exhibition | Year: 2014
World's energy demand is on upsurge and Oil & Gas industry has been directed towards the exploitation of deepwater oil and gas resources. To make this operation successful petroleum industry is continuously demanding new innovative drilling technology that can be easily implemented. One of the constraints that hinders the deepwater exploration is its continuously shrinking narrow window between pore pressure and fracture pressure that further limits the reliability of old conventional riser drilling technique. Dual gradient drilling (DGD) is a managed pressure drilling that involves use of two different annular fluids for drilling a prospect providing a favorable annular pressure profile and simpler, safer & economical well design. In any of the rotary drilling operation, drilling hydraulics is the most complicated and least understood drilling variable as it involves complex relationship between drilling fluid, drill bit and formation. Riserless drilling, one of the type of DGD, eliminates the use of marine riser (u-tube is imbalance) and involves use of an additional subsea mud pump at seabed which, supplements to the complication for hydraulics computation as compared to conventional drilling. In drilling HPHT deepwater wells, drilling fluid is constantly exposed to its own column pressure and formations geothermal gradient which subsequently affects the mud rheology and density. These altered rheological parameters leads to inadequate hole cleaning and lowers the drilling efficiency. High temperature in the wellbore cause's fluid expansion and high pressure causes fluid compression and these changes get extremely severe as water depth and drilling depth increases. Hence it becomes necessary to consider the HPHT effects on Equivalent Circulating Density (ECD) and to correct & optimize the hydraulic program to ensure the best utilization of the hydraulic energy for effective hole cleaning. This paper presents a detailed study of Well hydraulics for riserless drilling considering the HPHT effect on Equivalent Circulating Density and its optimization so as to ensure riserless drilling operation is conducted in safe and effective manner. Also the paper is concluded with some recommendations on operational and design strategies. Copyright 2014, Society of Petroleum Engineers.
ShunChang W.,Schlumberger |
YiMing J.,Schlumberger |
ChunJiang Z.,Schlumberger |
BaiLin W.,Schlumberger |
And 4 more authors.
SPE Drilling and Completion | Year: 2010
This paper describes a real-time case study to prevent mud loss and blowouts while drilling a high-pressure gas well in Tarim basin, China. The complex geological structure, high tectonic stresses, and overpressured-and fractured-reservoir formations in the field present a huge challenge to drilling. Of the seven wells drilled in the field in 2005, two did not reach target depths, four experienced huge mud loss, and the other experienced a blowout, resulting in lost control of the well. In early 2006, PetroChina teamed up with Schlumberger and Petroleum University of China to form a collaborative technical group to develop a better understanding of mud-loss and blowout mechanisms. The key component of the study was to establish a mechanical Earth model (MEM) based on offset well data before drilling, update the model using downhole monitoring and logging data during drilling, and predict a safe mud-weight window in real time. Real-time prediction of a safe mud-weight window with annular-pressure monitoring helped ensure that downhole annular pressure was maintained within the safe mud-weight window during drilling and tripping. The study resulted in a × 17 reduction in mud loss and ×10 reduction in total nonproductive time (NPT), which is mainly because of mud-loss reduction and elimination of an extra casing. A better understanding of mud-loss/blowout mechanisms was achieved, and guidelines for preventing mud loss/blowouts specific for this gas field were developed. © 2010 Society of Petroleum Engineers.
Verma G.,Jaypee Institute of Information Technology |
Verma V.,Indian Institute of Technology Roorkee |
Sharma D.,Jaypee Institute of Information Technology |
Kumar A.,Petroleum University |
And 2 more authors.
International Journal of Smart Home | Year: 2016
Unicode font is used in coding system that assign a unique code to every symbol of scripts irrespective of their platform, and language. The Greek Unicoder receives 16-bit hexadecimal code of alphabet. The device has been designed to convert Greek language into different languages that our people could understand. This Unicode reader code has been implemented on 28nm FPGA platform called Kintex-7 FPGA. In this paper we are using frequency scaling technique and Design goal. In this paper power analysis is our main concern and we have studied about the power analysis at different frequencies keeping the temperature constant at 25 degree Celsius and maintaining the constant air flow. © 2016 SERSC.
Bhatia J.C.,Petroleum University |
Srivastava J.P.,Oil and Natural Gas Corporation |
Sangwai J.S.,Indian Institute of Technology Madras |
Sharma A.,Indian Institute of Technology Hyderabad
Society of Petroleum Engineers - International Petroleum Technology Conference 2012, IPTC 2012 | Year: 2012
Water Alternate Gas (WAG) injection methods are the derivative of gas injection methods, wherein water and gas are injected intermittently. WAG injection can lead to improved oil recovery by combining better mobility control and contacting upswept zones and by leading to improved microscopic displacement. Gas trapping in the reservoir after WAG process is an important parameter that affects the recovery of oil. Trapped gas refers to the immobile gas saturation remaining after the rock is flooded with oil or water. Trapped gas creates significant hysteresis effect (during drainage and imbibition) and reduces the relative permeability of water in the mixed wet or oil wet reservoirs. In this work, gas trapping phenomena is presented for different WAG methods for a Indian Brownfield, namely, single, five cycle WAG, tapered WAG, five cycle WAG with Hydrocarbon gas (HC) and CO 2 gas. Experiments are carried out on the recombined fluid in the core flooding apparatus at the reservoir conditions. The crude oil and gas is obtained from the separator at separator conditions and recombined at the reservoir conditions of 120°C and 230 kg/cm 2 at reservoir gas-oil ratio (GOR) to become representative of the reservoir fluid. The actual core sample is obtained from the field and is used for the study. The water and gas injection rate used for this study are 20 and 10 cc/hr, respectively, for all the experimental studies. Two types of gases are used for WAG method, namely, hydrocarbon gas (collected from the field and having about 90 % methane by composition in mole %) and CO 2 gas. The results on the saturation of phases and Land's trapping constant have been calculated for several cases of production life cycle and for different WAG methods.
Parekh-Pandit R.P.,Pandit Deendayal Petroleum University |
Deendayal K.D.,Petroleum University
SPE Middle East Oil and Gas Show and Conference, MEOS, Proceedings | Year: 2013
Technological advances in coiled tubing, Coiled Tubing handling equipment, and application techniques have provided new opportunities for the effective, economic use of Coiled Tubing in various fields of petroleum industry. The technology is still in the process of testing its boundaries and limitations. However, this is a necessary phase in the learning curve. Probably the most logical approach is to consider the market or application niches best suited to coiled tubing drilling technology. Evolution of the coiled tubing Production process is one of the most exciting and fastest growing sections of the coiled tubing industry. In Dual zone completion, production is conventionally carried out using parallel tubing string completion or tubing annulus completion. In this case implementation of artificial lifts is difficult. This difficulty could be overcome by the use of coiled tubing, sliding sleeve and an anchor. This paper presents a review of the CT capabilities that can be used in dual hole completions. This paper intends to discusses the guidelines of applicability of Coiled Tubing and design considerations for using Coiled Tubing as a sucker rod and also as production string in dual zone along with the pros and cons of coiled tubing. We have concluded our paper with some relevant recommendation on some operational and design strategies as well as future direction for integration of additional variable. Copyright 2013, Society of Petroleum Engineers.
Zhang J.,China University of Petroleum - Beijing |
Fan J.,China University of Petroleum - Beijing |
Zhang L.,China University of Petroleum - Beijing |
Wang P.,Petroleum University
Well Testing | Year: 2010
Risks of leakage accident in testing wells with high temperature and high pressure are analyzed. This paper selects Gaussian model as the basic model of diffusion, and takes the main factors that influence leakage and effective height of leakage into account. The initial injection process of gas leakage neglected by Gaussian model is modified, and a preliminary analysis of the model is carried out. The 3D simulation analysis of diffusion process is done with examples. The diffuse rules of leaked gas with high temperature and high pressure are obtained, and the explosion area is divided apart. It is of great significance for avoiding potential accidents, for guiding the emergency rescue plan better and ensuring the testing safety in gas wells with high temperature and high pressure.
Zupeng D.,Petroleum University |
Yuetian L.,Petroleum University |
Yanyan L.,Petroleum University |
Kun A.,Shengli Oilfield Co.
Well Testing | Year: 2011
Stereo injection and production to horizontal well in buried hill reservoirs is a new developing method, whose macro flow laws need to be definite. Based on numerical simulation method, the horizontal well flooding position, the horizontal well injection-production method and the horizontal segment length are optimized respectively. The results show that the development effect of bottom injection is better than the cases of top injection and corresponding position injection, that the development effect of horizontal well zigzag flooding is better than the case of over-below flooding, and that the horizontal segment length should not be too long with considering the border effect. The optimized results can be guidance for reservoir development. It can also provide a new technical mean for developing the buried hill reservoirs efficiently.