Geysers Area Research Articles

Observations of Nighttime Winds Using Pilot Balloons in Anderson Creek Valley, Geysers, California

Nighttime drainage or downslope winds along the east-facing slope of Anderson Creek Valley located in the Geysers area of northern California are examined using pilot balloons as air parcel tracers. Observations made over four nights show a persistent pattern of winds. Before sunset strong westerly winds blow into the valley. These winds are believed due to the late afternoon sea breeze. Drainage winds become fully developed within 2 h after sunset. The drainage wind has an average speed of approx.3 m s/sup -1/ regardless of the speed of the ambient wind. The drainage layer thickness grows at a rate of approx.80 m per kilometer of downwind distance. Balloons in the drainage current quickly spread throughout the shallow, sidewall canyon containing Anderson Creek. The transition from the local valley wind system to the free, ambient wind occurs at about ridge height, i.e., /sub 5/00 m above the valley basin, for weak ambient winds, and at /sub 3/00 m above the valley basin for strong ambient winds.

Developments in West Coast Area in 1979

New-field discoveries in California were down in 1979 from the previous year. The total exploratory footage drilled was slightly lower, but the total number of successful exploratory wells was up 19% from 1978. One new oil field and 5 new gas field discoveries were reported in California. None of these discoveries appear to be of major size. During 1979, hydrocarbons were discovered in commercial quantities for the first time in Oregon--the Mist Gas field, in the northwestern corner of the state, in Columbia County. A pipeline was constructed for initial production in late 1979. This discovery has spurred drilling and leasing activity. Mobil drilled a second deep exploratory well in Oregon, to 10,412 ft, which was subsequently abandoned. Only 1 shallow oil and gas explora ory well was drilled in Washington State this year. As yet it has not been completed. Development drilling in California, although down from 1978, continued at an active pace and is related largely to steam-flood projects. Production of oil outstripped additions to reserves by 285.8 million bbl in 1979. Geothermal activity increased in California's Imperial Valley and Geysers area. Southern California Edison Co. has begun construction of a 10-Mw generating plant near Brawley in the Imperial Valley. Two other geothermal projects in the Imperial Valley sponsored by Southern California Edison include the development of a 50-Mw unit near Heber and a prospective 10-Mw plant south of the Salton Sea. Westmoreland Geothermal Associates also have plans to develop a plant in the valley. In the Geysers area, Sacramento Municipal Utility District plans to construct a 55-Mw plant. The Geysers capacity is expected to increase to 1,238 Mw by the end of 1982.

The Reich case: Economic implications of depletion allowances

The Reich case was tried in the 1969 Tax Court of the United States and the Court held that geothermal steam is a gas and is an exhaustible resource at The Geysers field. Accordingly, all geothermal steam producers are now entitled to deduct as current expense the intangible costs of developing and drilling geothermal steam wells and all producers who can demonstrate that their geothermal steam resource is depletable are entitled to what is now a 22 percent depletion allowance. The key expert witness in the case was Dr. Henry J. Ramey, Jr. and a summary is presented of his monograph which was submitted as evidence. His conclusion, based on a reservoir engineering analysis, was that the geothermal resource at the Big Geysers area had, as of 1968, a 20 to 46 years of productive life remaining. In the economics portion of the paper, it is demonstrated that the corporate income tax discriminates against risky and capital-intensive industries such as oil and gas and geothermal. The central economic argument in favor of percentage depletion allowances and expensing privileges is that these provisions remove the discriminatory bias of corporate income taxes. The economic consequences of depletion allowances are 1. — a short- and long-run increase in production; 2. — a short- and long-run increase in investment in renewal-exploration, discovery, and development; 3. — lower prices; 4. — a ratio of reserves to output—the Life Index—which tends to be constant; 5. — a short-run increase in profits which encourages the entry of new firms and a long-run situation in which average rates of return are again equalized across industries.

Civil Engineering Features of Geothermal Power Plant

Geothermal power is harnessed by releasing steam from a geothermal reservoir through bore holes and conducting it through a heavily insulated pipe system to a turbine-generator unit. Low magnetic readings, a negative gravity anomaly, elliptic topographic expressions, and recent nearby volcanism indicate the heat source is intruded magma at relatively shallow depth. Selection of a plant site is determined by: (1) proximity to producing steam wells; (2) esthetic blending with the environment; (3) competent foundation material; and (4) the optimum economic overall site development evaluation. A plant consists of a turbine-generator building and an induced draft cross-flow type cooling tower. The structures are designed to use corrosion-resistant materials. Seismically, the geysers area typically has many microearthquakes with an absence of large magnitude earthquakes. Other factors involved are domestic water steam suppliers and steam productivity, environmental considerations, the hydraulics of the cooling water cycle, and jurisdiction by various state and county agencies.

Geothermal Drilling in California

Although drilling for geothermal energy is quite similar to drilling for oil and gas, there are some aspects of it that are unique. The high temperatures associated with geothermal wells affect the circulating system and the cementing procedures as well as the design of the casing and drilling string. The unique problems must be coped with along with those normally encountered. Introduction Geothermal energy is simply the energy derived from the earth's magmatic heat. This would include all the products of geothermal processes, naturally occurring products of geothermal processes, naturally occurring and artificially induced. Steam, hot water, and minerals are some of the most important direct products of geothermal resources.Geothermal power was recognized first in Italy in 1904 as a future source of energy. It was not until the mid-1950's that the U. S. became seriously interested in geothermal power, the chief reason being that until this time other energy sources were plentiful.In 1955, a drilling program began in the Geysers area of California. The first geothermal power generator in the U. S. began operation in the Geysers in 1960. Since that time the drilling activity hasincreased substantially and several generating plants have been constructed, The total capacity of the Geysers is presently in excess of 300 megawatts (Mw), which ranks the U. S. as the second leading nation in geothermal power production. This activity stimulated the exploration for geothermal resources in other areas of the country, especially in other parts of California.The Imperial Valley of California is another center of geothermal interest. Unlike the Geysers area, which produces dry superheated steam, the Imperial Valley produces hot brine. There are presently several wells being drilled in the latter area and there have been many proposals to utilize the available geothermal power. The Imperial Valley Geology The Imperial Valley is essentially a flat, featureless, alluvium-filled basin trending northwestward from the Gulf of California to and including the Coachella Valley. The sediments filling the Imperial depression are primarily sandstones, shales, claystone, and conglomerates deposited by the ancestral Colorado River as it formed its delta. The sediments range in thickness from 8,000 ft in the northeastern Coachella Valley to 17,000 ft in the southwestern Imperial Valley.Three major fault systems, all with northwesterly trends, are present in the Imperial Valley. The San Andreas zone travels along the northeast side of Coachella Valley. The San Jacinto and Elsinor fault zones are on the northwest side of the Imperial Valley. Most of the numerous faults in the three systems have right lateral and vertical movement, with the northeast block structurally higher than the south-west block. Surface Locations Most locations for drilling operations pose no real problem since the terrain is nearly flat. The primary problem since the terrain is nearly flat. The primary surface problem in the Imperial Valley is the extreme heat to which the personnel and the machinery are exposed. Water for the drilling operations is usually obtained from one of the many irrigation canals that cross the Valley or from water wells. JPT P. 1033

Microearthquakes at The Geysers Geothermal Area, California

Microearthquakes in The Geysers area of northern California were recorded for 3 weeks with a radio-telemetry array of eight seismograph stations in order to examine their distribution with respect to the area developed for geothermal power. Locations were determined for 53 earthquakes within about 10 km of The Geysers. Most epicenters lie in a zone about 4 km long and 1 km wide passing through the geothermal field along a principal fault zone. Focal depths in this trend range from near surface to about 4 km. A composite fault-plane solution indicates dextral strike-slip faulting on a NNW-striking plane subparallel with the regional fault pattern. The results of this study suggest that accurate mapping of microearthquakes can be useful in the exploration for geothermal resources, if the earthquakes studied here are not somehow caused by development of the field.

Geothermal Developments in The Geysers Area, California: ABSTRACT

The Geysers area is about 90 mi north of San Francisco. The rocks in the area are Jurassic-Cretaceous Franciscan graywacke, sandstone, shale, greenstone, serpentine, and extrusive rocks belonging to the Clear Lake volcanic series of late Pliocene to late Pleistocene age. Volcanic activity is believed to be the cause of the abnormal high heat flow. Drilling was started by Magma and Thermal Power Companies in 1955 and Pacific Gas and Electric's first plant of 12,500 kilowatt-hours (KWH) electrical generating capacity went into operation in 1960. The power output was more than doubled in 1963 and again in 1967 for a total of 55,000 KWH. A fourth plant of 27,500 KWH is under construction and new generating units of 55,000 KWH each are being planned. To date Magma-Thermal have drilled 42 wells in three producing areas comprising a total of 300 acres. The wells range in depth from 1,500 to 5,000 ft. Steam capable of generating about 150,000 KWH is actually developed. The reservoir is a fractured sandstone and the occurrence of thermal alterations in a linear trend have led many to conclude that the fracturing is associated with faulting. The fluid exists in the reservoir as superheated steam with a pressure of about 500 lb. Successful stepouts drilled by Union, Signal Oil and Gas, and by Geothermal Resources International have expanded significantly the potentially productive area and the early estimates of 600,000 KWH power potential for the area may be conservative. End_of_Article - Last_Page 565------------

The self-sealing geothermal field

The self-sealing geothermal field

Geothermal Energy: ABSTRACT

The search and utilization of geothermal energy commenced in Italy in the early 1900s. Today, Italy produces sufficient power from geothermal energy to operate its entire network of electric railroads. This amounts to approximately 400,000 kw. One hundred areas in 15 different countries are being explored for geothermal energy. Other countries which are currently utilizing geothermal energy are: Iceland, for domestic and industrial heating; Japan, for electrical power and recovery of salt from sea water; and New Zealand, U.S.A., and Mexico for electrical power. The Geysers area of northern California was first investigated for its geothermal potential in 1922. The project was not successful as there was sufficient electrical power being produced from fossil fuel and by hydroelectric plants. The rapid industrialization and population explosion in the western states have led to an increase in demand for energy. From 1945 to 1960, electrical power production increased 239% for the nation and 252% in the western states. The FPC predicts a 275% rise nationally by 1980, based on 1960 power demands, with a forecast of 320% rise for the western states. To meet these demands for electrical power, all forms of energy known to man must be harnessed. The first commercial geothermal power production, in the United States, began at The Geysers in 1960 at the rate of 12,500 kw. In April 1967 the capacity was increased to 56,000 kw. It is estimated that the capacity can be increased to 1,000,000 kw. Recognizing geothermal energy as a source of power, the U.S. Geological Survey is conducting a nation-wide investigation of all geothermal areas which may have this potential. The state Bureaus of Mines of California, Oregon, Nevada, Utah, and New Mexico have conducted their own studies to evaluate their geothermal areas. Locating a geothermal area which may have commercial power potential is difficult. The most obvious areas of hot springs and geysers currently are being investigated. It is conceivable the areas which may hold the greatest potential cannot be detected at the surface. The drilling and development of a geothermal area are extremely hazardous and expensive, but technical problems will be solved, and costs reduced, as future increased power demands escalates the exploration for geothermal power. End_of_Article - Last_Page 1905------------

The geyser area near Beowawe, Eureka County, Nevada

The geyser area near Beowawe, Eureka County, Nevada