South-central Louisiana Research Articles

No. 1 Play in U.S.A.--South Louisiana Tuscaloosa Trend, 1975-80: ABSTRACT

Since the May 31, 1975, discovery of Tuscaloosa production at False River field in West Baton Rouge Parish, Louisiana, the Tuscaloosa trend of south-central Louisiana has developed into the most active deep exploratory play in the United States. Drilling activity since the discovery of the False River field has resulted in the additional discovery of 13 Tuscaloosa gas-condensate fields, one Tuscaloosa oil field, three Austin Chalk discoveries, and one Wilcox discovery. As of March 1980, 241 permits have been issued by the Louisiana Department of Conservation. Of this number, 119 are wildcats which have been drilled or are drilling below a depth of 15,000 ft (4,572 m). The success ratio for wildcats is one of six, or 16 2/3%, and field extension and development drilling ha resulted in a success ratio of one of two, or 50%. There are more than 4 million acres (1,600,000 ha.) under lease in the trend; 129,680 acres (51,872 ha.) have been placed in Tuscaloosa drilling units by the Louisiana Department of Conservation. Some of the most significant fields discovered along the trend are the False River field, West Baton Rouge Parish; Moncrief, Judge Digby, and Moore-Sams fields in Pointe Coupee Parish; Port Hudson, Irene, and Profit Island fields in East Baton Rouge Parish; and Lockhart Crossing field in Livingston Parish, Louisiana. Proved reserves of 4 Tcf of gas and 400 MM bbl of condensate have been established. In addition, available seismic and subsurface data indicate the future reserve potential of the Tuscaloosa to be estimated at 16 Tcf of gas. A detailed subsurface and stratigraphic study of the existing fields to date should serve as a guide for locating other major reserves along the trend. End_of_Article - Last_Page 1552------------

Evolution of Sand-Dominant Subaerial Phase, Atchafalaya Delta, Louisiana

In 1972 the Atchafalaya River delta of south-central Louisiana evolved into a subaerial form, which is now prograding at a rapid rate. This latest stage of development has focused attention on one of the most dynamic geologic events of this century in coastal Louisiana. The delta has resulted from (a) steady diversion and capture of Mississippi River flow by the hydraulically more efficient Atchafalaya River, (b) progressive and rapid filling of the Atchafalaya basin, (c) initiation of a subaqueous delta when clay deposition increased significantly in Atchafalaya Bay (early 1950s), and, finally, (d) appearance of a subaerial delta following delivery of coarse sediment to Atchafalaya Bay (early 1970s). Detailed bathymetric surveys, as well as estimates of new land areas using Landsat data, confirm rapid subaerial growth of the Atchafalaya delta since 1972. Bathymetric data taken in 1977 indicate that approximately 15.8 sq mi (40.9 sq km) of Atchafalaya Bay is now occupied by subaerial delta (above the low-tide level). The subaerial phase of development is dominated by deposition of coarse sediment. In this dynamic setting the coarsest sediment particles available to the Lower Atchafalaya River (fine sand) are carried as suspended load during floods. During these flood periods rapid accretion of subaerial delta lobes occurs. Abnormally high flood discharges during the period 1972-75 played an important role in the initiation and rapid evolution of the subaerial delta phase. Major environments of deposition and sedimentary deposits that make up this deltaic sequence are analogous to those that form subdelta components of the modern bird-foot delta of the Mississippi River. The chronology of subaerial development suggests that reentrainment and redeposition of scoured lake and channel-fill deposits during peak floods are linked to the rapid growth of the subaerial distributary-mouth bars documented in this paper.

Seasonal Bird Populations in a South Central Louisiana Bottomland Hardwood Forest

Seasonal Bird Populations in a South Central Louisiana Bottomland Hardwood Forest

A Distributed Computer Network for Oilfield Computer Production Control

Computer production control is becoming more important as an aid infield operations. It can be used profitably if it is reliable and flexible, and if it can be supported and maintained adequately. A distributed computer network can be an economical and effective way to meet varying field needs, provide reliability and flexibility, and assure continuous support. This provide reliability and flexibility, and assure continuous support. This paper describes such a system. paper describes such a system. Introduction Shell Oil Co. is implementing a distributed computer network for oilfield computer production control (CPC). This paper describes the network, shows how it is being used to meet several varied CPC applications, discusses advantages of the network approach, and presents some early results. CPC applications require that computers be involved directly in oilfield information gathering and processing, in the control of certain oilfield functions, and in the dissemination of operating information and results. To be effective, CPC systems must be highly reliable. They also must be very flexible to meet continuously changing requirements; and they must be economical to install, operate, and maintain. After assessing the many requirements, the primary cost factors, and the state of the art, Shell selected a distributed computer network to serve the Production Dept. The network is a system in which the CPC computers are physically located in or near the fields on CPC. However, these "field computers" are in on-line communication with a central computer for system support and information management. Services provided by the central computer include data analysis and storage, the generation of sophisticated reports, program and data file development and maintenance, and an interface with the corporate production information and accounting systems. Background Shell installed a pilot CPC system starting in 1970. That system performs rather routine functions of data gathering, warning, automatic well testing, and field reporting for the West Lake Verret field in south-central Louisiana. By late 1973, the following general pilot results and related observations were becoming clear.CPC can be an effective way to improve field operations and reduce operating costs in certain situations.Shell operates several fields in which the right type of CPC system - one uniquely designed to meet the requirements of each field - can be used profitably.The components of CPC systems (computers, software, communications, telemetry, meters, and end elements) can be made reliable. Also, the technology is continuing to improve.The potential economics of CPC are trending favorably as costs (particularly hardware costs) continue to remain stable or decrease, while benefits (reduced operating costs, increased production, and intangible results) continue to grow in significance.Certain key resources, especially the people needed to install, operate, and maintain CPC systems, are increasing in cost and are of limited supply. Based on these results and observations, a study was conducted to determine the best way to pursue new applications of CPC while maintaining proper constraints on the use of people and other limited resources. Experience with the pilot project led to the following principles that helped guide the study. JPT P. 1417

Environmental Management in Mississippi Delta System: ABSTRACT

The deltaic lowlands of the Louisiana coastal zone are exceptionally high in biologic productivity. Natural beauty and a rich cultural heritage further identify the coastal lowlands as a nationally important resource. As End_Page 1830------------------------------ the origin and ecology of the region are products of deltaic processes, it can be described appropriately as a self-maintaining natural system. Human activity has altered seriously the natural balance of the delta system. Massive environmental degradation has occurred during the past 30 years, and the entire system may soon collapse. Primary causes of deterioration include (1) flood-control and navigation improvement; (2) accelerated subsidence; (3) urban encroachment into wetlands; and (4) water pollution. A pilot study in south-central Louisiana has reviewed the problem of restoring the system's balance and allowing for projected growth and development. A multi-use management plan based on analysis of natural and human processes operating in the area and land-use suitability has been proposed. Highways and other public-works projects provide the mechanism for directing growth and development to environmentally suitable areas. Renewable resource areas are identified, and management priorities and guidelines outlined. A water-resource management program calls for conservation of local runoff as well as directing Mississippi River water and sediment for environmental maintenance and enhancement. Controlled delta building and introduction of supplementary water into estuarine basins will p rtly restore the delta-system balance. Other features of the plan include identification of transportation and utilities corridors, man-made barrier islands as protection against erosion and storm surge, geometries for dredge cuts and spoil designed to create habitat diversity and optimize hydrology. End_of_Article - Last_Page 1831------------

Mirex residues in wild populations of the edible red crawfish (Procambarus clarki).

Despite laboratory evidence of the extreme sensitivity of crawfish to the insecticide mirex, field studies and monitoring reveal no evidence of massive die-off or noticeable population declines. The residues obtained were so low as to be well below the levels capable of causing mortality of juvenile crawfish in the laboratory. It was concluded, therefore, that the present use of mirex in southcentral Louisiana is not an important threat to the crawfish industry.

Stratigraphy of Cibicides Carstensi Zone, Miocene of Louisiana

The fundamental stratigraphic unit of Gulf Coast subsurface geology is the biostratigraphic zone. These zones are named after benthonic Foraminiferida and are used widely in a time-rock sense by most workers in the region. Zonal nomenclature has developed informally within competitive oil companies. The middle Miocene Cibicides carstensi zone has been generally recognized for at least 15 years, but use of the name has been inconsistent, because no type section had been designated. The C. carstensi zone of south-central Louisiana, at its type locality, consists of four subzones. Boundaries of the zone and its components are defined on the basis of thin Foraminiferida-rich beds and distinctive electric-log markers. Relative abundance of foram tests in sediments provides an index to rate of clastic deposition. Lentils containing abundant Foraminiferida in a predominantly clastic sequence record episodes of relatively slow deposition. Abundance and composition of faunas in benthonic communities are controlled, in large part, by depositional rates and nature of substrate. Both these factors are dependent on tectonic history in the Gulf Coast. In that province stratigraphic thickness and sequence are closely related to faulting. Episodes of fault movement can be dated accurately by their influence on depositional thickness and lithologies in correlative strata on opposite sides of a fault. Stratigraphy, paleontology, and structural history consequently are inseparable. All three must be considered s multaneously in any geologic interpretation. Hydrocarbons of the C. carstensi zone accumulated in blanket sand bodies deposited under conditions of tectonic stability. Sands which have a sharp basal contact tend to be erratic and limited in areal distribution. These sands are thought to have been deposited on a steeply inclined or irregular submarine topography, during or immediately following spasms of tectonic activity. Such sands rarely produce hydrocarbons. Nodosaria angularis, new species is restricted to down-dip parts of the C. carstensi and underlying Textularia stapperi zones.

Stratigraphy of Cibicides carstensi Zone, Miocene of Louisiana: ABSTRACT

The fundamental stratigraphic unit of Gulf Coast subsurface geology is the biostratigraphic zone. These zones are named after benthonic Foraminiferida and are widely used in a time-rock sense by most workers in the region. Zonal nomenclature has developed informally within competitive oil companies. The middle Miocene Cibicides carstensi Zone has been generally recognized for at least 15 years, but use of the name has been inconsistent, as no type section had been designated. The C. carstensi Zone of south-central Louisiana, at its type locality, consists of 4 subzones. Boundaries of the Zone and its components are defined on the basis of Foraminiferida-rich lentils and distinctive electric-log markers. Percentage of foraminiferal tests per unit volume of sediment provides an index to rate of clastic deposition. Widely spaced lentils containing abundant Foraminiferida in a predominantly clastic sequence record episodes of relatively slow deposition. Abundance and composition of fauna in benthonic communities are controlled, in large part, by depositional rates and nature of substrate. Both of these factors are dependent upon tectonic history in the Gulf Coast. Stratigraphic thickness and sequence are closely related to faulting in this province. Episodes of fault movements can be dated accurately by their influence on depositional thickness and lithologies in equivalent strata on opposite sides of a fault. Stratigraphy, paleontology, and structural history are consequently inseparabl . All 3 must be considered simultaneously in any geologic interpretation. Hydrocarbons of the C. carstensi Zone accumulated in blanket sand bodies deposited under conditions of tectonic stability. Sandstones which have a sharp basal contact tend to be erratic and limited in areal distribution. These sands are thought to have been deposited on a steeply inclined or irregular submarine topography during or immediately following spasms of tectonic activity. Such sandstones rarely produce hydrocarbons. End_of_Article - Last_Page 1696------------

FLUSHING PATTERN OF NON-REACTIVE EFFLUENTS

In south central Louisiana non-reactive liquid effluents are introduced into man-made relatively straight prismatic canals which are comparatively narrow and have brackish watpr To study the flushing pattern of liquid effluents introduced into those canals (or eptuanes), a one-dimensional numerical model is considered for a simplified system consisting of a long straight gently sloping reach with a sinusoidal tidal variation at the mouth of the estuary, sinusoidal tidal v^iation with a phase lag and an attenuated amplitude at the upstream end, a variable inflow hydrograph, and a variable inflow or outflow. For this system, the continuity and momentum eauations are solved numerically by an explicit finite difference scheme. The output of the model describes the spatial and temporal variations in flow velocity (also in water depth and discharge) from which the flushing pattern is obtained for a liquid effluent introduced at any time during the tidal cycle at any section along the estuary. The numerical model is applied to Charenton drainage canal m south central Louisiana and good agreement is obtained between the velocities and stage elevations predicted from the model and recorded in the field. An IBIV 360/65 computer is utilized.

The 1967 Foray of the American Bryological and Lichenological Society in Louisiana and Texas

Participants on the American Bryological and Lichenological Society foray in August, 1967, collected 119 lichen and 63 moss taxa from selected areas in western Louisiana and eastern Texas. Thirty lichen taxa are new for Louisiana and 16 are new for Texas. The 1967 foray of the American Bryological and Lichenological Society, planned and led by the senior author, was held in western Louisiana and eastern Texas for two days preceding the meeting of the American Institute of Biological Sciences at Texas Agricultural and Mechanical University, College Station, Texas. About 20 bryologists and lichenologists (Fig. 1) participated in the foray, which began on August 25 at Hodges Gardens Motel near Many, Louisiana. The area along the common border of Louisiana and Texas, where much of the foray took place, is one of rolling hills, with occasional rock exposures (rare in the mid-Gulf Coastal Plain), covered by pine, hardwood, or mixed forest. Hardwood forest occupies the bottomlands along the Sabine River which forms the boundary between the two states. The dissected terrain and the siliceous rock outcrops (of Miocene age) provide a range of habitats for cryptogamic plants far greater than the usual for Louisiana. The senior author and his students have collected bryophytes along the Louisiana-Texas border, but lichens have received little attention from botanists of the area. Langlois, who collected cryptogams intensively in south-central Louisiana, apparently never visited the westernmost parishes. The rock substrates are a particularly good source of new state records as only six exclusively saxicolous lichen species have been previously reported for Louisiana. Of the 17 species of lichens collected on rock on the foray, only one, Buellia glaziouana, had been reported previously for Louisiana. Lichens and mosses collected during the foray are discussed separately in the following reports, and are listed at the end of the paper. No lists of liverworts were submitted by participants. Five collecting sites were planned for the foray; these are identified in the text as Stops 1-5, and are indicated by the same numbers in the lists of lichens and mosses. A sixth, unscheduled stop is identified in the Lichen Report as 2B.

Late Recent Rise of Sea Level

Radiocarbon dating of marsh peats in south-central Louisiana permits interpretations of relationships between former positions of land and sea. Past marsh surfaces, now buried at depths ranging from 4 to 40 feet, indicate the positive change in level that has taken place since their origin. Abundant evidence for a stillstand in sea level during the past 2000–5000 years affords a fixed datum for differentiation between eustatic sea-level rise and subsidence. The rate of subsidence in the study area is 0.24 foot per century. Results show a eustatic sea-level rise of approximately 23 feet in the interval between 7000 and 3650 years B. P. when stillstand was reached. There is no indication that sea level was higher than at present at any time during the interval studied.

Control of Petroleum Accumulation by Sedimentary Facies in South Louisiana: ABSTRACT

This paper, with the aid of electric logs and cross sections, presents some new ideas concerning the effects of sedimentary facies upon the accumulation of oil in south-central Louisiana. It covers the section from the Wilcox to the Cockfield. End_of_Article - Last_Page 2067------------

Blood Studies on Trichuris-Infested and Worm-Free Children in Louisiana 1

Abstract SummaryThe blood picture was studied in 550 rural white children 5 to 14 years old in south-central Louisiana. Of these 197 were infected with trichuris; 140 with trichuris and some other intestinal worm, usually ascaris; and 213 were worm-free. The blood picture was essentially the same in all groups, i.e., 11.22 to 11.52 grams hemoglobin per 100 cc. blood; 4.5 to 5.0 million erythrocytes per cmm. blood; mean corpuscular hemoglobin of 23.0 to 23.7 micro micrograms; and a relative lymphocytosis of 46.4 to 47.2 per cent. These children are known to suffer from undernourishment and it is suggested that most of them both parasitized and worm-free, suffer from a nutritional anemia. There is no evidence that the blood picture is effected by the trichuris infestation.