Effect of Directional Permeability on Sweep Efficiency and Production Capacity

1959 ◽  
Author(s):  
Bobby L. Landrum ◽  
Paul B. Crawford
10.2118/16-pa ◽  
1961 ◽  
Vol 1 (04) ◽  
pp. 277-286 ◽  
Author(s):  
M. Mortada ◽  
G.W. Nabor

Abstract The effects of anisotropic or directional permeability on the areal sweep efficiency and the flow capacity are examined. The paper points out the importance of taking directional permeability into consideration in planning a flood. It analyzes the two-dimensional flow pattern associated with the skewed line drive for a unit mobility ratio. The direct and staggered line drives are treated as special cases of the skewed line drive. Analytical expressions are developed for the areal sweep efficiency at breakthrough and the flow capacity. They are related to the spacing between like wells, the distance between a row of injectors and the nearest row of producers, and the degree of skewness of the line drive. The latter quantity is defined such that it is equal to zero for the direct line drive and equals one-half for the staggered line drive. The a real sweep efficiency and the flow capacity depend also on the orientation of the flood pattern with respect to the principal axis of anisotropy. The paper provides a simple method for determining the a real sweep efficiency and the flow capacity for a formation in which the permeability in the bedding plane is anisotropic. Introduction Directional or anisotropic permeability is manifested by the ability of the formation to conduct fluids more readily along certain preferred directions. This situation occurs in many producing formations and is usually attributed to depositional features in which the sand grains are oriented in a preferred direction. In some cases it results from the formation of a major and a minor fracture system. Directional permeability should be taken into account in many phases of the production and exploration activities. Recognizing its existence in the formation of interest and planning accordingly can lead to increased recovery and substantial savings. For instance, the areal sweep efficiency in a water flood depends to a great extent on the orientation of the flood pattern with respect to the principal axis of permeability. Anisotropic permeability is specified by the directions of its three principal axes and the permeability along each axis. The principal axes of permeability are mutually perpendicular. This paper deals with the areal sweep efficiency at breakthrough and the flow capacity for formations with anisotropic permeability. The flood pattern considered consists of alternate rows of injecting and producing wells. The rows of wells are parallel and form a developed, skewed line drive which is illustrated in Fig. 1. The staggered and direct line drives are treated as special cases of the skewed line drive.


1968 ◽  
Vol 8 (03) ◽  
pp. 260-268 ◽  
Author(s):  
D.A.T. Donohue ◽  
J.T. Hansford

Abstract Substantial evidence indicates that many petroleum producing horizons contain naturally occurring, ordered fracture systems and that within a particular geologic zone, vertical fractures induced in wellbores often will be directed along a particular compass direction. Both conditions will seriously alter the fluid displacement behavior within reservoirs. In this study the effect of induced fracture orientation and length on sweep efficiency is determined for a five-spot pattern. In general, it is assumed that all wells are fractured and directed along the same compass direction. Using the electrical analog to steady state, two-dimensional fluid flow in porous media, boundary conditions are obtained from which flood fronts are tracked numerically. The numerical computations require a particle tracking routine for approximating flood front histories. It is shown that recovery is sensitive to the length and orientation of fractures for the pattern studied. With the proper design of fracture-pattern systems, recovery can be enhanced considerably. Introduction Hydraulic fracturing introduced in 1949, gave the industry a rather inexpensive means of increasing the fluid injection or production capacity of wells. It has been used with particular success to increase the production rate of wells completed in tight formations, such as in western Pennsylvania where producers have fractured in depleted or near-depleted fields and observed economic responses. Once the natural energy declines in such a reservoir where all wells have been fractured, waterflooding is generally suggested as means of further increasing recovery. Of the dual objective sought in waterflooding -- high injectivity and high break-through sweep efficiency - the former condition can be obtained if all wells in the flood pattern are fractured; the latter condition should depend on the nature of the fracture system. Considerable theoretical work has been published on the nature of fractures induced in boreholes. Although discussion persists concerning the possibility of forming a horizontal at a given point within the wellbore, it is generally conceded that only vertical fractures will develop below a given depth, i.e., where the fracturing pressure is less than the overburden load. Given the fact that fractures will be vertical in most cases of interest, it is also important to know whether there is order to fracture orientations within a given geological region. Kehle has suggested that in tectonically relaxed areas of uncomplicated geology, the stresses are fairly uniform and all fractures in the region should be parallel. Dunlap arrived at a similar conclusion in a theoretical investigation of localized stress conditions surrounding the borehole. He concluded that most vertical fractures are propagated in a preferred azimuthal direction. Fraser and Pettitt, in extending these theoretical suggestions to a specific field case, used an impression packer to record both a vertical fracture and the orientation of this fracture in the wellbore of a well in the Howard Glasscock field, Tex. Use of this information enhanced the waterflood recovery of the field. Anderson and Stahl also used impression packers on three fractured wells in the Allegheny field, N. Y., and found that the fractures were oriented more or less along the same compass direction. Orientation of the fractures in this manner depends on the stress condition within the formation during fracturing. Elkins and Skov have demonstrated that a natural, oriented, vertical fracture system exists within the Spraberry field. SPEJ P. 260ˆ


2015 ◽  
pp. 5-24 ◽  
Author(s):  
B. Zamaraev ◽  
T. Marshova

The article examines the state of production capacity of Russian industry. It is shown that in spite of certain positive shifts, the rate of technological modernization in recent years has been insufficient for marked progressive changes in the capacity structure and quality. In contrast to the industrial growth after the crisis of 1998 that took place in the presence of significant reserves of capacity, the current level of idle capacity is much lower. The lack of mass input of modern and high-tech industries objectively limits the possibilities of import substitution and economic growth.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 507-515 ◽  
Author(s):  
David Skuse ◽  
Mark Windebank ◽  
Tafadzwa Motsi ◽  
Guillaume Tellier

When pulp and minerals are co-processed in aqueous suspension, the mineral acts as a grinding aid, facilitating the cost-effective production of fibrils. Furthermore, this processing allows the utilization of robust industrial milling equipment. There are 40000 dry metric tons of mineral/microfbrillated (MFC) cellulose composite production capacity in operation across three continents. These mineral/MFC products have been cleared by the FDA for use as a dry and wet strength agent in coated and uncoated food contact paper and paperboard applications. We have previously reported that use of these mineral/MFC composite materials in fiber-based applications allows generally improved wet and dry mechanical properties with concomitant opportunities for cost savings, property improvements, or grade developments and that the materials can be prepared using a range of fibers and minerals. Here, we: (1) report the development of new products that offer improved performance, (2) compare the performance of these new materials with that of a range of other nanocellulosic material types, (3) illustrate the performance of these new materials in reinforcement (paper and board) and viscosification applications, and (4) discuss product form requirements for different applications.


TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 631-638
Author(s):  
FREDERIC KREPLIN ◽  
HANS-JOACHIM PUTZ ◽  
SAMUEL SCHABEL

Paper for recycling is an important fiber source for the production of corrugated base paper. The change in production capacity toward more and more packaging papers affects the composition of paper for recycling and influences the paper quality. This research project investigated the influence of the multiple recycling of five different corrugated base papers (kraftliner, neutral sulfite semichemical [NSSC] fluting, corrugating medium, testliner 2, and testliner 3) on suspension and strength properties under laboratory conditions. The corrugated board base papers were repulped in a low consistency pulper and processed into Rapid-Köthen laboratory sheets. The sheets were then recycled up to 15 times in the same process. In each cycle, the suspension and the paper properties were recorded. In particular, the focus was on corrugated board-specific parameters, such as short-span compression test, ring crush test, corrugating medium test, and burst. The study results indicate how multiple recycling under laboratory conditions affects fiber and paper properties.


2015 ◽  
Vol 2 (1) ◽  
pp. 12-22 ◽  
Author(s):  
L. Pylypenko ◽  
K. Kalatur

Heterodera schachtii Schmidt, 1871 is one of the most economically important pests of sugar beet (Beta vulgaris L.) worldwide. It is also widespread in most sugar beet growing regions in Ukraine causing serious yield reduction and decreasing sugar content of sugar beet in infested fi elds. An advanced parasitic strategy of H. schachtii is employed to support nematode growth, reproduction and harmfulness. In intensive agriculture systems the nematode control measures heavily rely on nematicides and good agricultural practice (crop rota- tion in the fi rst place). But alternative strategies based on nematode resistant sugar beet cultivars and hybrids are required as none of nematicides approved for the open fi eld application are registered in Ukraine. Here we review the achievements and problems of breeding process for H. schachtii resistance and provide the results of national traditional breeding program. Since the beginning of 1980s fi ve sugar beet cultivars (Verchnyatskyi 103, Yaltuschkivska 30, Bilotcerkivska 45, BTs-40 and Yuvileynyi) and seventeen lines partly resistant or toler- ant to H. schachtii have been obtained throughout targeted crossing and progenies assessment in the infested fi elds. The further directions for better utilization of genetic sources for nematode resistance presented in na- tional gene bank collection are emphasized. There is a need for more accurate identifi cation of resistance genes, broader application of reliable molecular markers (suitable for marker-assisted selection of nematode resistant plants in the breeding process) and methods for genetic transformation of plants. Crop cash value and national production capacity should drive the cooperation in this fi eld. Knowledge as well as germplasm exchange are thereby welcomed that can benefi t breeding progress at national and international level.


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