Flow behavior of N2 huff and puff process for enhanced oil recovery in tight oil reservoirs
In the present work, the potential of N2 huff and puff process to enhance the recovery of tight oil reservoir was evaluated. N2 huff and puff experiments were performed in micromodels and cores to investigate the flow behaviors of different cycles. The results showed that, in the first cycle, N2 was dispersed in the oil, forming the foamy oil flow. In the second cycle, the dispersed gas bubbles gradually coalesced into the continuous gas phase. In the third cycle, N2 was produced in the form of continuous gas phase. The results from the coreflood tests showed that, the primary recovery was only 5.32%, while the recoveries for the three N2 huff and puff cycles were 15.1%, 8.53% and 3.22%, respectively.The recovery and the pressure gradient in the first cycle were high. With the increase of huff and puff cycles, and the oil recovery and the pressure gradient rapidly decreased. The oil recovery of N2 huff and puff has been found to increase as the N2 injection pressure and the soaking time increased. These results showed that, the properly designed and controlled N2 huff and puff process can lead to enhanced recovery of tight oil reservoirs.
The application of N2 huff and puff for IOR in fracture-vuggy carbonate reservoir
Abstract In Tahe Oilfield, Tarim Basin, NW China, although the carbonate reservoir displays poor porosity and permeability in matrix, the fractured-vuggy system distributes in a random, discreet and discontinuous way, which could yield high oil rates once the fractured-vuggy system is connected by production wells. The fractured-vuggy carbonate reservoirs consist a group of large caves which are inter-connected with high permeable fractures. Due to the lack of powerful and suitable IOR (Improved Oil Recovery) strategies, the depletion recovery is usually applied at the beginning for a fractured-vuggy carbonate reservoir. During the depletion process, the elastic energy of the cave formation starts to decrease, which will cause insufficient liquid supply. Then, the water was injected to improve the oil recovery when the energy (pressure) is the main reason for the insufficient production performance of the well. However, if the high water cut is the main reason, alternative IOR techniques such as the N2 huff and puff method could be utilized. This paper mainly researches the application of N2 huff and puff in a fracture-vuggy carbonate reservoir, where the critical parameters for designing the N2 huff and puff process are proposed. In addition, the proposed method is applied to Well SX to serve as a practical example. Based on the three-dimensional (3D) quantitative sculpture geological model and the dynamic production analysis, the critical parameters for N2 huff and puff are obtained by numerical simulation. In addition, the obtained parameters are validated by the field data, which proves that the proposed method can be applied to design the critical parameters for simulating the N2 huff and puff process in a fractured-vuggy carbonate reservoir.
Handbook Of Microemulsion Science And Technology
HISTORICAL PERSPECTIVE Microemulsions-A Historical Overview, B. Lindman and S.E. Friberg STRUCTURAL ASPECTS AND CHARACTERIZATION OF MICROEMULSIONS Thermodynamics of Microemulsions I, W.K. Kegel, J.T.G. Overbeek, and H.N.W. Lekkerkerker Thermodynamics of Microemulsions II, E. Ruckenstein Microscopic Models of Microemulsions, G. Gompper and M. Schick Lattice Monte Carlo Simulations of Micellar and Microemulsion Systems, R. Rajagopalan, L. A. Rodriguez-Guadarrama, and S.K. Talsania Effects of Alcohol Chain Length and Salt on Phase Behavior and Critical Phenomena in SDS Microemulsions , A. M. Bellocq Aggregation Behavior in One-Phase (Winsor IV) Microemulsion Systems, S. Ezrahi, A. Aserin, and N. Garti Ionic Microemulsions, J.-L. Salager and R.E. Anton Supercritical Microemulsions, G.J. McFann and K.P. Johnston Characterization of Microemulsions by NMR, B. Lindman, U. Olsson, and O. Soderman Rheological Properties of Microemulsions, M. Gradzielski and H. Hoffmann Light Scattering Studies of Microemulsion Systems, D. Langevin and J. Rouch Characterization of Microemulsions Using Fast Freeze-Fracture and Cryo-Electron Microscopy, J.R. Bellare, M.M. Haridas, and X.J. Li Characterization of Microemulsions by Electrical Birefringence, Z.A. Schelly REACTIONS IN MICROEMULSIONS Organic Reactivity in Microemulsions, C.A. Bunton and L.S. Romsted Application of Microemulsions in Enhancing Sensitivity of Reactions in Spectroscopic Analysis, R. Guo and X. Zhu Preparation of Ultrafine Particles of Metals and Metal Borides in Microemulsions, J.B. Nagy Microemulsion-Mediated Synthesis of Nanosize Oxide Materials, K. Osseo-Asare Time-Resolved Luminescence Quenching in Microemulsions, M. Almgren and H. Mays Structure and Reactions in Microemulsions Formed in Near-Critical and Supercritical Fluids, J.L. Fulton Electrochemical Studies in Microemulsions, S. Qutubuddin Polymerization in Microemulsions, F. Candau Enzymatic Reactions in Microemulsions, K. Holmberg APPLICATIONS OF MICROEMULSIONS Applications of Microemulsions in Enhanced Oil Recovery, V. Pillai, J.R. Kanicky, and D.O. Shah Microemulsions in Pharmaceuticals, M. Malmsten Microemulsions in Cosmetics, P.A. Aikens and S.E. Friberg Microemulsions in Foods, S. Engstrom and K. Larsson Application of Microemulsions as Liquid Membranes, J.M. Wiencek Application of Microemulsions in Textile Cleaning Using Model Detergency Tests, H.-D. Dorfler FUTURE PROSPECTS The Future of Microemulsions, J. Sjoblom and S.E. Friberg