Acoustic and Vibrational Enhanced Oil Recovery

George V. Chilingar, Kazem Majid Sadeghi, Oleg Leonidovich Kuznetsov

• Editore: Wiley-Scrivener
• Anno: 2022
• ISBN:
  9781119760177
• Edizione: 1
• Argomento: Physical Sciences
• Categoria: Energy

ACOUSTIC AND VIBRATIONAL ENHANCED OIL RECOVERY

Oil and gas is still a major energy source all over the world, and techniques like these, which are more environmentally friendly and inexpensive than many previous development and production technologies, are important for making fossil fuels more sustainable and less hazardous to the environment.

Based on research they did in the 1970s in Russia and the United States, the authors discovered that oil rate production increased noticeably several days after the occurrence of an earthquake when the epicenter of the earthquake was located in the vicinity of the oil producing field. The increase in oil flow remained higher for a considerable period of time, and it led to a decade-long study both in the Russia and the US, which gradually focused on the use of acoustic/vibrational energy for enhanced oil recovery after reservoirs waterflooded. In the 1980s, they noticed in soil remediation studies that sonic energy applied to soil increases the rate of hydrocarbon removal and decreases the percentage of residual hydrocarbons. In the past several decades, the use of various seismic vibration techniques have been used in various countries and have resulted in incremental oil production.

This outstanding new volume validates results of vibro-stimulation tests for enhanced oil recovery, using powerful surface-based vibro-seismic sources. It proves that the rate of displacement of oil by water increases and the percentage of nonrecoverable residual oil decreases if vibro-energy is applied to the porous medium containing oil.

Audience:

Petroleum Engineers, Chemical Engineers, Earthquake and Energy engineers, Environmental Engineers, Geotechnical Engineers, Mining and Geological Engineers, Sustainability Engineers, Physicists, Chemists, Geologists, and other professionals working in this field

1
Introduction

Physical fundamentals of vibration and acoustic actions on the reservoir for improving the oil yield and increasing the development tempo of depleted and water-encroached oil fields are presented in this book. It is shown that the area of most efficient application is reservoirs with crudes characterized by a high water content and heterogeneity, low permeability, high shaliness, etc. The developed techniques are ecologically neutral and do not cause damage to the well-designed elements. The book may be useful to students, scientists, and engineering-technical personnel engaged in geophysics and development of petroleum fields.

The book is devoted to the theoretical and applied aspects of physics of the porous media saturated with oil, gas, and (or) water. A special attention is devoted to the hydro- and thermodynamic phenomena emerging in such media upon spreading within them of elastic waves with frequencies between infrasound and ultrasound. For expert analysis of the reviewed phenomena, the authors expended years of painstaking work (creating theoretical models and conducting specialized physical experiments on the reservoir models in the in situ conditions). In the 1970s to 1990s, the authors designed a complicated special equipment for the laboratory and field experiments and then conducted experimental and industrial testing. Beginning in 1990s, the interest increased in the vibration and acoustic technologies to an increasing oil-gas production in Russia, USA, France, Brazil, and China. The authors believe that the results achieved will be useful first of all for specialists designing new methods of improving well productivity. A useful information, however, will be found here also by geophysicists creating new technologies of rock diagnostics and of seismic and acoustic identification of commercial hydrocarbon accumulations.

Having read the book, the reader will get the idea of major aspects in theory and practice of vibration and acoustic effect on the porous media. It is important that the reviewed technologies are nondamaging to the environment. The authors believe that the book will initiate a burst of interest not only in the hydraulics and flow physics in the field of vibration but also in the nonlinear geophysics. The most important is the synergetic physicochemical effects forming the foundation of seismo-geochemistry and the study of the Earth’s gas respiration in the process of its oscillatory motions.

Research presented in this book was initiated partly because of the recorded dependence of the rate of oil production on earthquake occurrences in seismically active areas (Surguchev et al., 1975 [33]). It was noticed that several days after the occurrence of an earthquake with the epicenter located in the vicinity of the oil-producing oil field, the rate of oil production increased and remained higher than the pre-earthquake level for a considerable period of time. It was also noticed in the soil remediation studies (e.g., Sadeghi et al., 1992 [28]) that sonic energy applied to the contaminated soil increases the rate of hydrocarbon removal and decreases the percentage of residual hydrocarbons. Modern world oil and gas-producing industry is dominated by the application of artificial methods of affecting oil reservoirs. The application of diverse action systems and methods enabled an implementation of the intensive oil fields’ development at high oil production tempo. The major accrual in the oil reserves in the future is anticipated in the areas of ever more complex geologic and geographic environment, significantly distant from the areas of oil consumption.

Thus, developing novel efficient enhanced oil recovery technology [e.g., Electrical Enhanced Oil Recovery (EEOR)] is imperative. At present, after a field development is ended, more than half of oil reserves remain subsurface. This means that, currently, the fields with residual oil reserves of over 0.5 BT (billion tons) are written off annually. If such amount of the oil loss is maintained, then a stable increase of oil production cannot be guaranteed for an extended period of time due to limited oil reserves.

The following major reasons may be identified for a decreased oil yield:

• – The operation of capillary forces preventing oil displacement from smaller pores of a micro-nonuniform porous medium;
• – Unfavorable interrelation between the mobilities of the displaced and displacing liquids;
• – Geological heterogeneity of the productive reservoir.

Almost 90% of oil in Russia, for example, is recovered from the fields which experienced poor sweep efficiency during the waterflooding.

Another important trend is development of the techniques improving interrelation of the mobilities between the oil and water. For the application of one or another action method on the oil and gas reservoirs, it is important to know where exactly the oil is remaining after flooding. Due to a low sweep efficiency by water, the non-recovered oil in the flooding process, will constitute 60% to 90% of the entire reserve. About 10% to 40% of the oil is not recovered due to a low sweep efficiency by waterflooding.

In the development of low-viscosity oil fields with productive reservoirs of moderate heterogeneity, the major cause of incomplete oil recovery is associated with the capillary forces. Oil recovery improving methods in such fields must be the elimination (total or partial) of capillary forces causing the problem.

If a field under development is characterized by a strong geological heterogeneity of productive reservoirs, then the oil yield improving methods should first of all include increase in the sweep efficiency by the water in waterflooding.

At the development of high-viscosity oil fields, a substantial fraction of non-recovered oil is associated with unfavorable mobility ratio. That is why the means of increasing the oil yield must be directed first of all to increasing viscosity of the displacing fluid and decreasing viscosity of the displaced oil.

Most of the known methods of increasing the oil yield includes the means of eliminating, in part or in full, the manifestation of one of the three aforementioned major causes of lowering efficiency of oil displacement from the productive reservoirs. However, the application of these means in the late development stages gives disappointing results. One of the major causes of the low efficiency of the methods is that they ignore natural tendency of hydrocarbon fluids to move when subjected to the action of gravity and capillary forces. This explains the attention of petroleum engineers and geologists to vibration and acoustic technologies capable of taking these tendencies into account.

Various options are created of base technologies and technical solutions for industrial implementation. Depending on technology and the applied technical means, vibration and acoustic methods may be used for the solution of the following tasks:

• – Increasing the productivity of producing wells in which the application of conventional methods turned out impossible or of low efficiency;
• – Increasing the oil and gas yield from the water-flooded low-productivity reservoirs;
• – Increasing sweep efficiency during waterflooding.

Vibration technologies of increasing well productivity are most popular as a result of their relative simplicity and low cost. They are based on various techniques of passing the energy from the borehole vibration source to the reservoir by way...