Seismograph Operations Research Articles

Investigation of the stable and unstable states of seismographs using poles and zeros pattern

In this study, a simple Simulink model was designed and presented which can describe the overall operation of seismograph based on the desired input and output response.By converting Laplace to seismograph equations and by defining Numerator and Denominator fractions to Num. and Den. (Numerator and Denominator) transfer WWSSN (World-Wide Standard Seismographic Network) functions, the changeability of pole-zero was taken into consideration which indicates the stability and instability of the system layout with respect to pole - zero layout. In fact, the poles and zeros are placed in the seismograph response based on frequency, amplitude and phase (FAP) and are analyzed well. Through this method can also be used to study seismograph transfer function to predict the seismograph output in environments with different seismic noise and to select the most appropriate value for the parameters controlling the output of the device.

A Study of Seismograph Setup in Schools to Educate and Awareness Programme for Students

Satish Saha*, R Vijaya Raghavan, ANS Sarma, G Suresh, A Sateesh, PR Jitendar and D Srinagesh CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad-500007, India _____________________________________________________________________________ Abstract: In this article efforts have been made to describe how education and awareness programme on seismograph setup helps the school students to learn more about the occurrence of earthquakes and safety measures to be adopted during the earthquake. Soon after the Bhuj earthquake of January 26, 2001, a mission mode project in seismology was initiated by the Government of India with a view to create new scientific and technology (S&T) base and appropriate human resources for mitigating the adverse impact of earthquake hazard. Ministry of Earthquake Sciences (MoES), Government of India has sponsored this project to CSIRNational Geophysical Research Institute (NGRI), Hyderabad to setup 80 broadband educational seismographs in secondary schools in the earthquake prone region of Western Maharashtra. A educational seismograph setup in secondary school campus creates interest among schools students to know more about a felt earthquake in the area or destructive teleseismic earthquakes. The schools teachers shall be trained on operation of seismograph, seismic data retrieval, analysis and locating the earthquakes. The trained teachers disseminate this knowledge to the school students year after year. It also aims at motivating scientists for spreading knowledge beyond the boundaries of their institutions to create awareness among the students.

Petroleum Developments in Africa in 1958

Petroleum production in Africa for 1958 established a new all-time high of 31,930,880 bbls. which represents an increase of 72% over 1957. Egypt alone recorded a 33% increase in its production over the preceding year, and Egypt still dominates the production picture. However, Egyptian production represented only 69% of the Africa total in 1958, in contrast to a figure of almost 90% in 1957. Gabon, Algeria, and Nigeria were largely responsible for this change. One hundred forty-one exploratory wells were completed in Africa in 1958, of which 18% were successful. Eight discoveries were reported from Nigeria, 6 from Algeria, 4 from Libya, 3 from Gabon, 2 from Egypt, and 1 each in Angola and Morocco. Exploratory wells were completed but without success in Cameroun, Congo, Madagascar, Senegal, Somalia, British Somaliland, and Tunisia. One hundred ninety-one development wells were completed during the year, 74% of which were successful. A total of 2,214,392 ft. of hole was drilled in Africa in 1958, and at the end of the year 90 rigs were in operation. Geological-geophysical exploratory work was particularly extensive in Algeria, Libya, Madagascar, Morocco, Nigeria, Senegal, and Somalia. Party-months of various types of exploratory work for the whole of Africa were as follows: surface geology--629, seismograph--774, gravity--313, ground magnetometer--70, air-borne magnetometer--11, and structure drill--66. These represent all-time highs for surface geology, seismograph, gravity and magnetometer operations.

Case History, Pincher Creek Structure and Field: ABSTRACT

The Pincher Creek structure lies in the southern part of the Foothills Belt of Alberta. Seismograph operations started in the area of the structure in 1943 as a part of the survey being carried on in the region and has been carried on periodically into 1953. The shooting was partly by the refraction method. The discovery well is the Pincher Creek No. 1, LSD 15, Sec. 24, T. 3, R. 29 W. 4. Subsequently successful wells, the Marr No. 1 and the Bonertz No. 1, were drilled 7½ and 4½ miles, respectively, and in that order northwest of the discovery. The Schrempp No. 1 was drilled low on the structure in an attempt to find oil but only had a short section of the pay zone above the gas-water line. The Huddleston No. 1 is the most recent completion. It has modified somewhat previous ideas of the nature of the structure and has made a local change in the extent of the reservoir. The pay zone is in Mississippian dolomites and limestones with a stratigraphic sequence similar to that at Turner Valley. The gas is in intergranular porosity zones and in general permeability occurs as the result of fracturing in the reservoir. Most of the entire productive section has been cored with consequent good control of reservoir factors. End_of_Article - Last_Page 2616------------

A SEISMIC REFLECTION QUALITY MAP OF THE UNITED STATES

A reflection‐quality map of the United States has been prepared by a subcommittee of the Program and Arrangements Committee for 1950–51. The map designates as good, fair, or poor to NG all sedimentary areas of the United States in respect to reflection quality in seismic explorations. The map may be used in the planning of seismograph operations. Reflection quality is a function of many factors.

Operations Symposium: ABSTRACT

a. Camp Maintenance and Operation, Northwest Seismic Surveys, Limited. b. Seismograph Operations on Foot. c. Seismograph Operations with Horses, Carter Oil Company. d. Seismograph Operations Using Small Tractors and Trailers. e. Seismograph Operations with Weasels, Geophysical Service Incorporated--Pierson Ralph. f. The Helicopter as Used on Gravity Operations, United Geophysical Company--Wayne Phares. End_of_Article - Last_Page 2251------------

Developments in Louisiana Gulf Coast in 1949

In 1949, 956 wells were drilled in the Louisiana Gulf Coast. Of this number, 261 or 27.3 per cent were classified as exploratory wells and 695 or 72.7 per cent as field development wells. The number of exploratory wells more than doubled those in 1948. Of the 261 exploratory wells, 93 or 35.2 per cent were successful. The number of exploratory wells with their success percentage follows: new-field wildcats 133--26.3 per cent successful; new-pool wildcats 28--50.0 per cent successful; shallow-pool tests 2--50 per cent successful; deeper-pool tests 10--20 per cent successful; outposts 88--46.5 per cent successful. Of the 695 development wells, 528 or 76 per cent were successful and 167 were failures. There was a 19.0 per cent increase in number of wells drilled in 1949 with 956 as compared with 803 in 1948. These figures include only new holes drilled and do not include work-overs in shallower sands. The 35 new-field discoveries include 18 oil fields, 11 condensate fields, and 6 gas fields. Of this number, 13 were completed off shore. Thirty-two of the new-field discoveries were credited to the seismograph, two to subsurface and seismograph, and one unknown. There were several dry holes which added knowledge of stratigraphy. Seismograph operations decreased considerably during the last half of the year with only 2,537 crew weeks reported for the year. Leasing decreased approximately 50 per cent from 1948 with about 1,527,292 acres taken. The most active area was along the Miocene trend. Drilling declined considerably during the summer but became active again during the fall months.

Developments in Louisiana Gulf Coast in 1948

During 1948, 803 tests were drilled in the South Louisiana district. Of these, 129 or 16.1 per cent were rank wildcat exploratory tests and 674 or 83.9 per cent were field development tests. The 129 rank wildcat tests resulted in the discovery of 28 new fields. All successful field exploratory wells are classified as follows: new-pool wells, 29; shallower-pool wells, 3; deeper-pool wells, 8; and outpost wells, 38. Of the 674 field development tests, 463 or 68.9 per cent were successful and 211 were failures. There was an increase of 24.3 per cent in the number drilled in 1948 over 1947. The 28 new field discoveries include 13 oil fields, 11 condensate fields, and 4 gas fields. Of great significance is the fact that 7 of the new fields were discovered in the open waters of the Gulf of Mexico, 3 of which are oil fields, 2 condensate fields, and 2 gas fields. Seismograph operations are credited with having led to 22 of the new-field discoveries, subsurface led to 2, and a combination of seismograph and subsurface was responsible for the remaining 4. The small decrease in the number of seismograph crews operating in offshore waters was equalized by an increase in the number of inshore crews. The number of gravity-meter crews operating in the offshore areas decreased almost to zero during the year. This appears to indicate a general decline in offshore geophysical exploratory and reconnaissance activities. The number of land gravity meter crews increased to a maximum in the summer months and then decreased during the remainder of the year. The most significant exploratory activity in 1948 was made in the offshore Miocene trend. There has been a noticeable increase in geophysical and leasing activities in the area northeast of the Mississippi River.

Developments in Louisiana Gulf Coast in 1947

In 1947, 646 wells of all classifications were drilled in the Louisiana Gulf Coast. Of this number, 166, or 25.7 per cent, were classified as exploratory wells and 480, 9r 74.3 per cent, as field-development wells. Of the 166 exploratory wells, 59, or 35.5 per cent, were successful. Their classification follows. Success Percentage New-Field Wildcats, 73 17.8 New-Pool Wildcats, 39 64.8 Shallower-Pool Tests, 7 85.7 Deeper-Pool Tests, 7 100 Outposts, 40 20 Among the 480 development wells, 395, or 82.3 per cent, were successful and 85 were failures. There was a 10 per cent increase in drilling in 1947, with 646 wells drilled, as compared with 586 in 1946. These figures include only new holes drilled and do not include work-overs that were completed in shallower sands. The 13 new-field discoveries include 7 oil fields, 2 gas-distillate fields and 4 gas fields. Only 2 of these fields, Holmwood, a faulted structure and Ship Shoal-Block 32, a new offshore salt dome, are considered at this stage of development to be of significance. Ten of the new-field discoveries were credited to seismic surveys and 3 to seismic and subsurface. Several dry holes added knowledge of stratigraphy. Two of these failed in attempts to extend regionally westward, the producing Massive Tuscaloosa sand of the Big Island field. One shallow dry hole located a piercement-type salt dome in the Gulf of Mexico. Seismograph operations continued at a steady pace throughout the year with an approximate total of 3,400 crew weeks reported. Most of these operations was along the coastal and offshore Miocene trend. Leasing continued at a high level. Approximately 3,000,000 acres were taken, the majority of which was along the coastal and offshore Miocene trend. Drilling continued at a stepped-up pace with most of it confined to intermediate and deep Miocene horizons. The trend of exploration was definitely along the Miocene belt which has offered, and still offers, unlimited prospective sands and promise of greatest returns.