Drilling Sequence Research Articles

Integration of Old and New Measurements To Optimize Redevelopment of the Lower Lagunillas Reservoir of Bloque IV, Lake Maracaibo, Venezuela

Summary The Lower Lagunillas of Bloque IV of the Bachaquero field is a supergiant reservoir that has been in production since 1956. We have carried out a pilot reservoir characterization study in the central part of the field, in which we have integrated all the available data into three-dimensional (3D) reservoir simulation models whose purpose is to optimize redevelopment of the area with horizontal wells. An analysis of the history of production was undertaken to gain an insight into the reservoir dynamics. This analysis indicated the inefficiency of gas injection in providing pressure support to the pilot study area and demonstrated the presence of active aquifer encroachment from the south. Anomalies in production behavior and fluid characteristics indicate both lateral and vertical compartmentalization of the reservoir. We have integrated Fourier transform infrared (FTIR) measurements of mineralogy from old cores with a comprehensive logging suite in a new well to re-evaluate older, sparse logging suites. The application of a mineral-based log evaluation and high-resolution processing of the new logs has led to a significant increase in estimates of oil initially in place in the study area. We have used a novel approach to estimate permeability in all wells in the study area. Combining these new evaluations with a revised geological model enabled us to recognize 11 geological layers throughout the area. Formation pressure measurements confirm that partial barriers to vertical communication exist between most of these layers. Cased hole saturation measurements and historical production data indicate an uneven sweep of these layers, such that five layers contain bypassed oil that could be recovered by horizontal wells. We have constructed very detailed simulation models that describe the lateral and vertical variation in petrophysical properties of each of these layers. These models have been used to select the optimum locations for horizontal wells and to optimize their drilling sequence and design. It is estimated that each of these wells could recover 1 to 1.5 million stock-tank barrels (STB) within 5 years. The first well drilled as a result of this study has produced dry oil at rates up to 469 BOPD from a zone not previously considered as a pay zone.

INTERSPERSAL OF KNOWN ITEMS IN A TREATMENT PACKAGE TO TEACH SIGHT WORDS TO STUDENTS WITH BEHAVIOR DISORDERS

The current study evaluated the effectiveness of using interspersal of known items in a treatment package to teach sight words to middle school students with moderate mental retardation and severe behavior disorders. An interspersal drill sequence was used to teach sight words related to reading the daily newspaper weather report. Results of the experiment indicated that students mastered the 10 sight words and showed some improvement in reading the daily weather report.

Osseointegrated implants in the maxillary tuberosity

Although the first and second molars usually are lost first in a partially edentulous maxilla, titanium implants are seldom placed more distally than at the second premolar site because of the poor quality of bone often found in the posterior maxilla. The present series encompasses 72 Brånemark implants placed in the third molar-tuberosity area with a success rate of 93% and an average follow-up after loading of 21.4 months. Moreover, two of the failed implants were in patients who had a simultaneous successful implant contralaterally. Keys to this high success rate include the meticulous identification and correction of all pathoses, modification of the drilling sequence to maximize initial implant stabilization, achievement of bicortical fixation whenever possible, gentle handling of the soft tissues and periosteum, and elimination or minimization of transmucosal occlusal loading during osseointegration and of nonaxial loading after connection.

Dynamic Modeling and Analysis of a High Speed Precision Drilling Machine

This paper describes the modeling and dynamic analysis of a high speed precision circuit board drilling machine. The drilling machine has two banks of movable drill spindles supported between parallel granite beams on an air bearing suspension. Each drill spindle is programmed to move laterally between the beams under the position control of a servo-feedback system. The drill spindles must complete a nominal 3.048 mm (0.12 in.) lateral move and a vertical drilling sequence every 200 ms. while maintaining an absolute positioning accuracy within 0.01778 mm (0.0007 in.). In order to meet these demanding specifications the dynamic behavior of the complete drill spindle/air bearing/granite beam system must be well understood. A specialized finite element model (FEM) is used to examine the dynamic responses of the critical components of this machine. The FEM code is capable of analyzing a sprung two degrees of freedom system moving on an elastic beam in an arbitrary fashion. The discussion concentrates on the engineering modeling considerations and compromises which were necessary to analyze the drilling machine with this computer code. The modeling rationale and use of experimental data to form an effective computer model capable of analyzing the dynamic behavior of the drilling machine are emphasized. Typical results from the finite element model are presented to illustrate the obtainable level of accuracy, detail and the limitations for modeling a system of this nature.

Exploration for Uranium Deposits in Grants Mineral Belt, New Mexico: ABSTRACT

Uranium ore deposits in the Grants Mineral Belt, New Mexico, occur in fluvial sandstones in the Jurassic Morrison Formation. Uranium mineralization is concentrated by a dark-gray to black substance that has been identified as humate derived from decaying vegetation. Black ore is truncated by overlying sandstone in at least two ore deposits, documenting an early age of mineralization. Ore deposits in the Grants Mineral Belt vary greatly in size and shape, generally occur in clusters, and often are difficult targets for drilling. Current exploration is largely a process of drilling in stages to (1) delineate favorable from unfavorable ground on a wide-spacing, (2) seek mineralization in favorable ground, and (3) conduct closely spaced drilling in mineralized areas. Criteria for favorability differ among exploration groups but generally includes (1) the presence of a host sandstone, (2) anomalous mineralization, (3) color of host rock, (4) presence of carbonaceous matter, and (5) position of area with respect to mineralized trends. A description of the sequence of drilling, from ore discovery to a mine on a one-square mile area at the Johnny M uranium deposit located in the east part of the Ambrosia Lake District, provides an example of the problem of predicting ahead of discovery where in a certain area, orebodies may occur. A study of the drill data at the Johnny M indicates the uranium ore is not related to specific features other than the presence of humate which is commonly associated with coalified plant fragments in mudstone-rich parts of the host sandstone. End_of_Article - Last_Page 688------------

The Role of Repetition Through Successive Approximations in the Acquisition of the Basic Skills*

ABSTRACT Repetition has been used as a language teaching device since antiquity and is the basis of the modern audiolingual drill sequence. Recent research indicates that many of the uses of repetition prescribed by the audiolingual method, such as the use of tapes in the language laboratory and in classroom drills, have not resulted in the student progress anticipated. An explanation for this phenomenon may be that the speed of phonic presentation on the tapes is too fast for the students' rate of listening comprehension, making it impossible for sounds and words to be identified in meaningful sequences. If the speed of presentation is reduced to a level at which the student fully comprehends all material on the tape, it seems reasonable to infer that the rate of listening comprehension will be increased substantially in terms of short‐ and long‐term mastery. The purpose of the present research was to examine language acquisition within the four skill areas of listening, speaking, reading, and writing, as it is affected by both non‐distorted retardation and repetition of speech. The subjects were divided into three groups: Group I heard taped materials which were reduced in speed to a point where comprehension was assured: Group II heard three repetitions, proceeding in three equal increments from base‐level comprehension to normal speed; Group III experienced the taped material at normal speed. All modifications in speed were effected by the speech compressor and were undistorted. During this experiment, the subjects' performance was differentially affected as a function of sex, language ability, and treatment, indicating a need for greater differentiation of teaching strategies within generally defined methodologies.

Repositioning of the Mandible Relative to the Temporomandibular Joint, Correcting Cases of Subarthrosis and Dysarthrosis

We measured the rise in the intraosseous temperature caused by freehand drilling or drilling through a surgical guide, by comparing different temperatures of irrigation fluid (10 °C, 15 °C, and 20 °C), for every step of the drilling sequence (diameters 2.0, 2.5, 3.0, and 3.5 mm) and using a constant drilling speed of 1200 rpm. The axial load was controlled at 2.0 kg. Bovine ribs were used as test models. In the guided group we used 3-dimensional printed surgical guides and temperature was measured with a thermocouple. The significance of differences was assessed with the Kruskal-Wallis analysis of variance. Guided drilling with 10 °C irrigation yielded a significantly lower increment in temperature than the 20 °C-guided group. When compared with the 20 °C freehand group, the reduction in temperature in the 10 °C guided group was significantly more pronounced at all diameters except 3.5 mm. Finally, when the 10 °C-guided group was compared with the 15 °C groups, the temperature rise was significantly less at 2.5 and 3.0 mm than with the guided technique, and at 3.0 mm compared with the freehand technique. We suggest that the use of 10 °C pre-cooled irrigation fluid is superior to warmer fluid for keeping temperature down, and this reduces the difference between guided and freehand drilling.