Conditions Of Wells Research Articles

Heuristic Approach for Renovating a Monitoring Network Measuring Sea Water Intrusion into the Coastal Aquifer

AbstractCoastal aquifer management requires rapid and effective decision making as regards rapid ground water salinity and volume changes. This can be assessed only by means of an efficient sea water monitoring network that can lead to a more exact location of sea water intrusion and the ground water quality trends of the area of study and a hydrogeologist who understands the mechanism of the aquifer. This article proposes a “heuristic” approach for prioritizing aquifer areas for improving the monitoring network by adding new observation wells and renovating old ones. Such an approach improves aquifer control by recommending where additional and renovation observation wells are required regarding sea water intrusion along coastal aquifers. The data in use for this approach consist of variables characterizing the hydrological situation in the aquifer and the technical conditions of sea water intrusion network observation wells within their ground water salinity environment. Applied to Israel’s coastal aquifer, this approach leads to a list of areas with highest priorities, most of which are located in the northern portion of the Coastal Plain aquifer. Such a list is a basis document for decision making, which helps focus upon areas where it is most urgent to improve the quality of information by drilling new observation wells or by rehabilitation of the technical conditions of the present sea water intrusion observation well network. Considering the results obtained, this approach may be considered as a means for requiring further input data for various hydrological models and for operational activities in the field.

Prediction of the Occurrence of Oil–Water Countercurrent Flow in Deviated Wells

Water circulation and oil–water countercurrent flow in a deviated well has been investigated in the present article. Flow patterns for the countercurrent flow have been identified. Two practical criteria based on the transport mechanisms of a liquid layer and a liquid droplet have been developed for determining the occurrence of oil–water countercurrent flow in deviated or multilateral wells. The criteria can also be applied to determine the liquid loading-up conditions of gas wells. Well deviation, well size, and oil density are the three major factors that affect the occurrence of oil–water countercurrent flow. The smaller the wellbore size, the larger the well deviation, or the denser the oil phase, the lower the minimum oil flow rate is required to avoid the occurrence of oil–water countercurrent flow or water circulation. Excellent agreement has been achieved between the model prediction and the field and laboratory observations. A modified equation has also been proposed for determining the water droplet size in oil–water wells.

Numerical Simulation of the Movement of Saltwater under Skimming and Scavenger Pumping in the Pleistocene Aquifer of Gaza and Jericho Areas, Palestine

The Pleistocene aquifers are important sources of water supply in both the Gaza and Jericho areas of Palestine. The aquifers are saline with freshwater lenses floating on saline bodies of water. It is important to investigate how to exploit these freshwater lenses without causing unnecessary mixing of the fresh and saline waters. The objective of this research is to investigate the feasibility of applying skimming and scavenger pumping as a means to exploit the freshwater lenses and to control saline water upconing in the aquifers. This study is the first to examine the movement of fresh and saline waters underneath skimming and scavenger wells in the aquifers of Gaza and Jericho. Two simulation models that couple density-dependent fluid flow and solute transport have been used to simulate and predict the movement of saltwater under different hydrogeological and operational conditions of skimming and scavenger wells in the two aquifers. The results show (for the Jericho Aquifer) that: the location of well screen has a strong control on the steady-state position of the fresh/saline water transition zone; the upconing mechanism appears to continue under skimming pumping until saline water enters the well screen even when the pumping rate is reduced; and for better salinity control it is necessary to place well screen against the gravel layers only and locate one screen segment in the saline water zone. The study shows (for the Gaza coastal aquifer) that the most important parameters affecting the movement of saline water under scavenger pumping are the relationship between recharge and pumping rates, the location of the well screen within the saturated thickness, the vertical permeability; and the transverse dispersivity. This study shows that saltwater upconing in Gaza aquifer can be controlled by operating a second well in the saline water zone so that the optimal ratio between saline water and freshwater pumping is 1:2 respectively.

Investigation of short wavelength intersubband transitions in InGaAs/AlAs quantum wells on GaAs substrate

InGaAs/AlAs quantum wells on GaAs substrates were studied for near-infrared intersubband transitions. The relationships between the properties of the intersubband absorption and the structural/growth conditions of the quantum wells were quantitatively investigated by using theoretical calculations based on a k-p perturbation method. The total intersubband absorption magnitude is shown to be closely related to the leakage of free carriers from the Γ minimum of the well to the X minimum of the barrier. This work provides important information for design of devices utilizing short wavelength intersubband transitions.

Method to improve water resources management in groundwater pumping areas and a case study

Abstract This paper describes the methodology used to obtain and analyse information concerning the operating conditions of wells, pumping equipment and irrigation systems to develop a sustainable groundwater management programme. A case study is provided to exemplify how the method was applied to attain a balance between the abstraction of groundwater for irrigation and the natural recharge of the aquifer.

REQUISITE AND QUALIFYING CONDITIONS OF ARTESIAN WELLS*1

GroundwaterVolume 23, Issue 1 p. 106-110 REQUISITE AND QUALIFYING CONDITIONS OF ARTESIAN WELLS*1 T. C. Chamberlin, T. C. Chamberlin U.S. Geological Survey Annual Report, 1885Search for more papers by this author T. C. Chamberlin, T. C. Chamberlin U.S. Geological Survey Annual Report, 1885Search for more papers by this author First published: January 1985 https://doi.org/10.1111/j.1745-6584.1985.tb02787.x * Reprinted from pages 131–141 of U.S. Geol. Survey Annual Kept. 5:131-175 (1885); and from pages 297–307 of Physical Hydrogeology, edited by R. Allan Freeze and William Back, Benchmark Papers in Geology, V. 72, Hutchinson Ross Publishing Company, Stroudsburg, Pennsylvania (1983). 1 The term artesian wells in this discussion is applied only to those that flow at the surface. Unfortunately the term is frequently used to denote deep wells that do not flow, a use that is to be condemned. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume23, Issue1January 1985Pages 106-110 RelatedInformation

ASPECTOS GEOQUÍMICOS DAS ÁGUAS SUBTERRÂNEAS DA REGIÃO DE BERTIOGA, ESTADO DE SÃO PAULO, BRASIL

The objective of this work was the characterization of conditions of ground-water wells in the above mentioned area. Methodology included an extensive sampling to obtain fundamental hydrogeological data, technical informations relating to well drilling and the relative position of wells vs cesspool. Geophysical prospecting (by electroresistivity methods) allowed us to determine the quality of the aquifers and the hydrogeological properties of the substratum. Most of the data were obtained by analysis (physicochemical and bacteriological) in situ, with the HACH Water Analysis Kit. Various degrees of potability were found, mainly on account ot the concentration ranges of Fe, NH 4 , NO 2 , and presence of coliform bacteria. The geochemical interpretation showed three types of water. The study of exchangeable bases revealed that there is a relationship between the chemical composition of waters and the lithology, and also the conditions of circulation of these waters within the rocks. Fluctuation of the concentrations of Fe and Cl are controlled by the distance from the beach, on the other hand the TDS, NH 4 and N0 3 , by conditions of circulation.

Aspectos geoquímicos das águas subterrâneas da região de Bertioga, Estado de São Paulo, Brasil

The objective of this work was the characterization of conditions of ground-water wells in the above mentioned area. Methodology included an extensive sampling to obtain fundamental hydrogeological data, technical informations relating to well drilling and the relative position of wells vs cesspool. Geophysical prospecting (by electroresistivity methods) allowed us to determine the quality of the aquifers and the hydrogeological properties of the substratum. Most of the data were obtained by analysis (physicochemical and bacteriological) in situ, with the HACH Water Analysis Kit. Various degrees of potability were found, mainly on account ot the concentration ranges of Fe, NH 4 , NO 2 , and presence of coliform bacteria. The geochemical interpretation showed three types of water. The study of exchangeable bases revealed that there is a relationship between the chemical composition of waters and the lithology, and also the conditions of circulation of these waters within the rocks. Fluctuation of the concentrations of Fe and Cl are controlled by the distance from the beach, on the other hand the TDS, NH 4 and N0 3 , by conditions of circulation.

Steam Injection Into the D and E Zone, Tulare Formation, South Belridge Field, Kern County, California

A portion of the D and E zone of the Tulare formation reservoir produced by pressure depletion for 22 years and by cyclic steam produced by pressure depletion for 22 years and by cyclic steam for 4 years. Because of low recovery, diminishing response, and well failures, new wells were drilled in 1969 to initiate continuous-steam injection. Cumulative recovery from the first-line wells is 26 percent of the original oil in place, more than double the estimated primary recovery. place, more than double the estimated primary recovery. Introduction The portion of the Tulare formation D and E zone sands discussed here is located in Sections 1, 2, and 12, T29S-R21E, in the South Belridge field, Kern County, Calif. Although the field was discovered in 1911, development of the area did not begin until demand for additional heavy crude occurred in 1943. Drilling started in May 1943, and by Dec. 1944 a total of 40 wells were producing on about 5-acre spacing. The oil rate reached a peak of 1,000 B/D and declined at a rate of 12 percent per year. Production was essentially by pressure depletion. Production was essentially by pressure depletion. Cyclic steam operations were initiated in the area in 1965 with excellent results. Although results were initially spectacular, decline was rapid despite repeat cycles. Well failures were numerous. Combustion and continuous-steam injection pilots were carried out in other parts of the field, Evaluation of these two methods indicated that the most desirable economics would be obtained by continuous-steam injection. This area was selected for a large-scale steam drive test. The test was initiated in April 1969. Oil recovery from May 1943 to April 1969 from this area was 3.2 million bbl, or 8.7 percent of the original oil in place. Pressure had declined to 180 psig. Pressure had declined to 180 psig. The test was carried out in two stages, with continuation dependent on the success of the first stage. Because of mechanical conditions of wells in this area, it was decided to redevelop the area using the best thermal techniques. Case histories of other steam injection projects have been reported in the literature. Reservoir Characteristics The over-all structure of the South Belridge field is a broad, southeasterly plunging anticlime, about 9 miles long and 2 miles wide, with sands deposited in a halo-like fashion around the flanks and with shaley sands across the axial portion. The study area is located on the northeast flank of Mobil Oil Corp's portion of the South Belridge field, as shown in Fig. 1. The area is about 1.7 miles long and 0.2 miles wide, with a dip of 7 degrees to the northeast. Structural contours, a type log, and the boundaries of the area are shown in Fig. 2. Within the D and E zone there are numerous individual sands that vary in thickness. This is shown in cross-section X-X' of Fig. 3, where the sands of the D zone are relatively thick down-structure but become thin, and in some cases disappear, up-structure. Cross-section Y-Y' of Fig. 4 also shows the variation in sand thickness and character. Sand correlations are often difficult. An isopach of net oil sand in the D and E zone is shown in Fig. 5. Within the area of study, the total net oil sand is a maximum of 130 ft down-structure and thins to 70 ft up-structure. P. 343

Elasticoplastic conditions of the filtration of a liquid in porous media

The article discusses questions in the theory of filtration in porous media, taking account of elastic, elasticoplastic, and plastic deformations. Parameters are introduced to evaluate irreversible effects in petroleum- and water-bearing strata, i.e., coefficients of the change in the porosity and the permeability. Equations are derived for filtration under unsteady-state and steady-state working conditions of wells and galleries. Two limiting cases, which allow analytical solutions, are separated out. In the general case, the equations of elasticoplastic filtration conditions are solved on an electronic computer. The numerial calculations show that the predominating effect results from taking account of the irreversible change in the permeability, depending on the change of the pressure in the stratum.

Calculation of Bottom-Hole Pressures For Deep, Hot, Sour Gas Wells

A somewhat neglected method of calculating bottom-hole pressures, that of Sukkar and Cornell, does not involve trial and error and is very fast for hand calculation; but it does not allow for the severe conditions of modern gas wells. Here the method is refined to extend the pressures and temperatures, to allow for sour gas, and to make results readily accessible for hand calculation. Introduction Modem trends in gas well drilling have been toward deep, hot, high-pressure completions. Currently, gas wells are being drilled to depths of about 25,000 ft in the southwestern U. S. As would be expected, bottom-hole pressures for these wells are high (about 16,000 psi), and bottom-hole temperatures are in excess of 400 deg. F. The gas produced from many of these deep wells is sour. To run bottom-hole pressure bombs is costly. and because the sour gas rapidly corrodes wirelines it may also be disastrous.There is often no indication of liquid in these wells, so it is possible to compute bottom-hole pressures from measured wellhead data. Of the many methods of computing bottom-hole pressure, perhaps the best known are - the method for static and flowing gas columns outlined in the State of Texas backpressure manual, and - the static and flowing gas column method described by Cullender and Smith. The static method described in Ref. 1 is the Rzasa and Katz Method II, related to the older Rawlins and Schellhardt method. The flowing method in Ref. 1 is a modification of the static column method, which is based on estimating flowing friction from the Weymouth gas flow equation. Although the static method in Ref. 1 can be used with several depth increments to provide reasonable answers for deep wells, the flowing method is not recommended for deep, high-rate wells. The Cullender and Smith method is based upon a mechanical energy balance and is generally reliable for both static and flowing gas columns. But methods in both Ref. 1 and Ref. 2 involve tedious trial-and-error solutions. The Cullender and Smith method is best solved by computer if many determinations are required. There is a method that does not involve trial and error, however, that is very fast for hand calculations; but surprisingly, this method has received very little attention and use. This paper is based on that technique.A method presented by Fowler, involves integrated values of the gas law deviation factor, Z, with pressure, and is a direct method of calculating static pressure, and is a direct method of calculating static bottom-hole pressure, assuming a constant average temperature. Sukkar and Cornell extended Fowler's analysis and presented a general approach to calculating both static and flowing bottom-hole pressures for pure natural gas. They derived a pressure integral for perfectly vertical pipe by assuming negligible kinetic energy change, steady-state isothermal flow, and no work done by the gas in flow. Sukkar and Cornell evaluated the integral generally in terms of pseudoreduced pressures. The integral contains the pseudoreduced pressures. The integral contains the gas law deviation factor as a function of pressure, but it is assumed that temperature can be treated as an average over the depth range of interest. This is not an important weakness in the method because a depth of interest can be broken into several intervals to provide accuracy. The integral is based on a mechanical provide accuracy. The integral is based on a mechanical energy balance for a flowing column and is essentially identical with the Cullender and Smith result. JPT P. 85

Controlled Waterflooding, Means Queen Reservoir

Abstract Controlled, balanced waterflooding techniques evolved from thorough planning in Humble Oil and Refining Co.'s 16,000-acre Means Queen five-spot water flood project as the logical solution to reservoir, proration, ultimate recovery and economic factors associated with secondary recovery operations. To achieve the goals of maximum oil recovery and minimum water production, the effectively controlled water flood requires an accurate and detailed reservoir description, planned rates of injection and production, accurate per-well performance data and monthly comparison of actual-to-theoretical performance to monitor water flood behavior and efficiency. Methods for accomplishing these requirements were preparation of a reservoir isopach describing the pore volume around each well; allocation of each well's producing or injection rate on the basis of PV fractions; installation of individual well metering equipment on both injection and producing wells; and development of a computer program, both to compare performance data monthly and provide schedules and records. The current success of the project demonstrates the effectiveness of these methods in combination with control procedures developed from reservoir performance. Secondary recovery has exceeded primary on some leases with current water-cuts of only 40 per cent. Ultimate secondary recovery is expected to be at least twice primary. Introduction The concept of controlled, balanced waterflooding evolved from a deliberately planned program of data gathering and analysis. For example, a planned coring program was incorporated in primary development to obtain basic reservoir data. This type of basic data could not have been secured, at any reasonable price, after primary development had been completed. Also, accurate secondary performance data have been obtained by the planned use of metering equipment and pressure interference tests. This project presented the problems of efficiently operating a prorated five-spot waterflood with varying spot sizes (a factor of 3:1) and varying spot PV (a factor of 10:1) to obtain maximum oil recovery while producing a minimum amount of water. In reviewing industry water-flooding activity, it was found that for various reasons (lack of sufficient reservoir data, mechanical conditions of wells, presence of multiple producing stringers open to common wellbores) only a moderate degree of control was exercised in carrying out most waterflood operations. Secondary recovery from many of these floods is approximately equal to primary, although secondary recovery up to two times primary recovery might have been possible under controlled waterflooding. Published and unpublished laboratory studies, as well as theoretical recovery calculations, indicate that more oil probably should be recovered if a more efficient displacement could be achieved, which should result in a longer period of maximum allowable producing rates and reduced water cycling. The potential for improved profit through controlled operations, where applicable, is substantial. For example, if secondary oil recovery in the Means Queen project could be increased by an amount equal to only 10 per cent of ultimate primary, an additional 1 million bbl of oil would be recovered. The decision was made to attempt a controlled waterflood in the Means Queen project. A balanced waterflooding concept, with a maximum degree of waterflood control exercised at the individual well level and with continuous monitoring of performance, was adopted to try to achieve the controlled operations desired. Reservoir CharacteristicsThe geographical location of the Means (Queen sand) field in northern Andrews County, West Texas, is shown in Fig. 1. Geologically, it is one of three separately prorated Queen fields in a single reservoir which lies on the eastern edge of the Central Basin Platform and extends into the Midland Basin of West Texas. These fields cover a combined area of about 35,000 acres with the Means (Queen sand) field covering about 16,000 acres. The reservoir, partially structural and partially stratigraphic, is a sand formation composed of two stringers occurring at a depth of about 4,100 ft. Log and core data in Fig. 2 are typical of the average reservoir characteristics. The lower sand member is the main producing zone since the upper sand is productive over very limited areas in the Means (Queen sand) portion of the reservoir. JPT P. 1385ˆ

The Requisite and Qualifying Conditions of Artesian Wells.Thomas C. Chamberlin

<i>The Requisite and Qualifying Conditions of Artesian Wells.</i>Thomas C. Chamberlin