Average Penetration Rate Research Articles

Winter wheat cultivars and nitrogen (N) fertilization—Effects on root growth, N uptake efficiency and N use efficiency

One way to reduce nitrate leaching losses from agricultural land is to increase crop nitrogen uptake efficiency (NUpE). In this aspect, root growth is an essential parameter, as more and deeper roots may improve the uptake from deeper soil layers and reduce nitrate leaching.This study examined the root growth, soil N depletion and yields of modern, commercial winter wheat (Triticum aestivum L.) cultivars in a two-year field experiment conducted on sandy loam soils. The effects of N fertilization on root growth and inorganic soil N utilization were quantified. In order to obtain data from the entire winter wheat rooting zone, the measurements were conducted to 2.3m soil depth. Root growth was studied by means of minirhizotrons. Parallel to the belowground measurements, the effects on aboveground biomass and N uptake were measured.In the two experimental years the average maximum root depths were 1.1 and 1.5m, respectively, and the average root depth penetration rates were 0.7 and 1.0mm°C day−1, respectively. N fertilization affected root density, which increased at least up to an application of 150kg N ha−1. The effect on root density was mostly seen in soil layers below 0.5m. N fertilization did not appear to affect root depth. There were root growth differences among the cultivars, though not strongly pronounced. The cultivar Hereford showed tendencies to higher root densities and deeper root growth, and this trend was correlated with a tendency to increased subsoil N depletion. Also, Hereford showed higher N use efficiency (NUE) compared to the other cultivars, as it produced more grain per N supply.Under the existing experimental conditions, a spring application up to 150kg N ha−1 did not increase the amount of nitrate left in the soil at harvest. In contrast, by an increase of N fertilization from 150 to 250kg N ha−1, on average 36 % of the extra 100kg N ha−1 was left in the soil. With a further increase from 250 to 350kg N ha−1, up to 90% of the extra N was left in the soil. The soil N increase at high N fertilization was most profound in the upper soil layer but also significant in the subsoil.

Drilling Engineering Design and Application of Well Fengshen-x601

Thick gypsum and glutenite exist in Fengshen block, which brings a lot of technical problems in drilling construction, therefore, the drilling engineering design optimization of well Fengshen-x601 was launched. Based on the drilling purpose and combined with the actual drilling information of offset wells, the five-intervalled well track and the well structure with four layer casing were adopted in this well, the HJT537GK high efficiency cone bit was recommended in glutenite formation, and saturated saltwater polysulfonate lubricating drilling fluid system was used in gypsum section, through these measures, safety drilling was guaranteed in this well. The average rate of penetration was 3.15 m/h in the actual drilling operation, which increased by 13% compared with the offset wells, in addition, there were no accidents and complex situations. These effective implementation provided some guidance and reference for drilling operations of in the similar block. Key words : Well track with five-intervalled; Gypsum; Glutenite; Drilling design; Fengshen-x601

A new type of whole oil-based drilling fluid

Abstract To meet the demand of ultra-deep well drilling and shale gas well drilling, organic clay and a oil-based filtrate reducer were developed and a whole oil-based drilling fluid formula was optimized. The performance of organic clay, oil-based filtrate reducer and the whole oil-based drilling fluid were evaluated in laboratory, and the whole oil-based drilling fluid was applied in drilling process for further test of its performance. Long carbon chain quaternary ammonium salt was used as modifying agents when synthesizing organobentonites. Oil-based filtrate reducer was synthesized with monomers of lignite and amine class. The laboratory tests show that the organic clay can effectively increase the viscosity of oil-based drilling fluid and the oil-based filtrate reducer can reduce the fluid loss. Their performances were better than additives of the same kind at home and abroad. The organic clay and oil-based filtrate reducer had great compatibility with the other additives in oil-based drilling fluid. Based on the optimal additives addition amount tests, the whole oil-based drilling fluid formula was determined and the test results show that the performances of the whole oil-based drilling fluids with various densities were great. The laboratory tests show that the oil-based drilling fluid developed was high temperature resistant, even at 200 °C, as density varies from 0.90 to 2.0 g/cm3, it still held good performance with only a little fluid loss, good inhibition, great anti-pollution, and good reservoir protection performance. Field application result shows that the performance of the oil-based drilling fluid is stable with great ability to maintain wellbore stability and lower density than the water-based drilling fluid; drilling bits can be used much longer and the average penetration rate is increased; the oil-based drilling fluid can satisfy the drilling requirements.

Research and Application of Recyclable Nitrogen Foam Horizontal Well Drilling Technology in the Daniudi Gas Field

AbstractThe Daniudi gas field is typically rich in ultra‐low permeability gas reservoirs in China, but its development is difficult. In this paper, pilot implementation of underbalanced horizontal well drilling technology was used in the H1 gas reservoir to develop the proved reserves effectively. Owing to the limitations of drilling technology and environmental protection, the recyclable nitrogen‐foam was ultimately chosen as a circulating medium. Through theoretical analysis and extensive laboratory tests, the optimal foaming agent composed of α‐olefin sulfonate and coco amine oxide was selected among six anionic surfactants/zwitterionic surfactants systems. The developed recyclable nitrogen‐foam has high salt resistance, temperature resistance and cycle performance, but weaker oil resistance. After the recyclable nitrogen‐foam horizontal well drilling technology was used in the H1 gas reservoir, the average rate of penetration of horizontal section increased by 118 %, ignition could be achieved during drilling and natural gas was of great potential for production. It was the first time to increase natural gas production capacity in the H1 gas reservoir using recyclable nitrogen‐foam horizontal well drilling technology. Successful application of this technology provides technical reserves for the effective development of the H1 gas reservoir.

Standing Versus Supine Radiographs to Evaluate Femoral Head Penetration in the Polyethylene Liner After Total Hip Arthroplasty

The linear penetration rates for ceramic femoral heads on conventional and highly cross-linked polyethylene were measured and compared with radiographs taken in the standing and supine position taken three weeks postoperatively and at final follow-up. Seventy-five patients (83 hips) with conventional polyethylene (group-1) and two hundred and seventy five patients (300 hips) with highly cross-linked polyethylene (group-2) were studied. Follow-up periods were 14.5years in group-1 and 8.6years in group-2. The average penetration rates in group-1 were 0.17mm/year in supine position and 0.18mm/year in standing position (P<0.05). On the other hand, the rates in group-2 were 0.03mm/year and 0.04mm/year respectively (P<0.05). Although there were statistical differences between groups, 0.01mm differences are probably not clinically relevant.

Analysis of Slimhole Drilling Technology Application in Shengtuo District

In order to develop marginal oil reservoir and save drilling cost,since 2006 Shengli Oilfield began to do research of slim hole drilling technology. After a summary trial of 13 wells in Shengtuo area, Analysis the existence of technical difficulties and solutions of slimhole. Preliminary formed a set of suitable technology for Shengli oil field, especially the slim hole drilling in Shengtuo area, The average penetration rate reached 18.39m/h, The average drilling period is 10.69d. The experience provides reference to the same kind of wells in shengli oilfield.

彰武断陷钻头优选及应用

彰武断陷位于松辽盆地南部，该地区地层岩性复杂，含有砾石层、火山岩层等难钻地层。初始完钻的12口井，平均机械钻速仅4.65 m/h，过低的机械钻速将严重影响到彰武断陷后期开发进程和经济效益。本文为解决彰武断陷区块钻井过程中机械钻速低这一问题，开发过程中采用主因子法对该区块各地层已使用的钻头进行了滚动评价，并将优选出的钻头序列用于指导下口井的钻头选型。2012年与2011年已钻井的平均机械钻速对比表明，利用主因子法优选出的钻头序列显著地提高了彰武断陷的机械钻速，主因子法可用于该地区的钻头选型。 Zhangwu fault depression is located in the south of Songliao Basin, where the strata’s lithology is complex, including difficult drilling formation such as gravel and volcanic rock formations. The average rate of penetration of 12 early drilled wells was only 4.65 m/h, which would seriously affect later development process and economic benefits of Zhangwu fault depression. To address this issue that the drilling process of Zhangwu fault depression experienced a low rate of penetration in this paper, principal factor method was adopted during development process for rolling evaluation on the used bits of each layer, and the selected bit sequences were used as a reference for bit type selection of next wells. The contrast of average rate of penetration in 2012 and 2011 shows that bit sequences selected with principal factor method dramatically improved the rate of penetration in Zhangwu fault depression, and principal factor method can be used for bit type selection in this area.

Application of rotary geosteering drilling in deep and thin reservoirs of Tarim Basin, NW China

Abstract Geological features, such as deep and thin reservoirs and unstable structure margin, occur in an oilfield of the Tarim Basin. To deal with these problems while drilling, a rotary geosteering drilling technique was introduced. The effect of its application was analyzed with an example, the shortcomings were summarized, and suggestions were given for other oilfileds. The feasibility and necessity of using rotary geosteering drilling were presented according to the engineering challenges in the oilfield, then the theory and main tools of it were introduced. Focusing on a double-step horizontal well in field application, the features and effects of this technique were elaborated. With rotary geosteering drilling in this well, the average rate of penetration was high and oil reservoir encountering rate was up to 82% in thin layers less than 1 m. Also, it avoided effortless weight on bit in sliding drilling method and made the wellbore more smooth and clean. The problems met were concluded, for example, the tools build-up rate was affected by several factors, measurement while drilling (MWD) signal was interfered, and the tools working performance was unstable. Suggestions were put forward for applying the rotary geosteering drilling technique in other oilfields.

Transcatheter Aortic Valve Replacement in Europe: Adoption Trends and Factors Influencing Device Utilization

The authors sought to examine the adoption of transcatheter aortic valve replacement (TAVR) in Western Europe and investigate factors that may influence the heterogeneous use of this therapy. Since its commercialization in 2007, the number of TAVR procedures has grown exponentially. The adoption of TAVR was investigated in 11 European countries: Germany, France, Italy, United Kingdom, Spain, the Netherlands, Switzerland, Belgium, Portugal, Denmark, and Ireland. Data were collected from 2 sources: 1) lead physicians submitted nation-specific registry data; and 2) an implantation-based TAVR market tracker. Economic indexes such as healthcare expenditure per capita, sources of healthcare funding, and reimbursement strategies were correlated to TAVR use. Furthermore, we assessed the extent to which TAVR has penetrated its potential patient population. Between 2007 and 2011, 34,317 patients underwent TAVR. Considerable variation in TAVR use existed across nations. In 2011, the number of TAVR implants per million individuals ranged from 6.1 in Portugal to 88.7 in Germany (33 ± 25). The annual number of TAVR implants performed per center across nations also varied widely (range 10 to 89). The weighted average TAVR penetration rate was low: 17.9%. Significant correlation was found between TAVR use and healthcare spending per capita (r = 0.80; p = 0.005). TAVR-specific reimbursement systems were associated with higher TAVR use than restricted systems (698 ± 232 vs. 213 ± 112 implants/million individuals ≥ 75 years; p = 0.002). The authors' findings indicate that TAVR is underutilized in high and prohibitive surgical risk patients with severe aortic stenosis. National economic indexes and reimbursement strategies are closely linked with TAVR use and help explain the inequitable adoption of this therapy.

One size does not fit all: Averaged data on household electricity is inadequate for residential energy policy and decisions

Residential electricity users need more detail than monthly bills to reduce consumption. With the emergence of technologies that provide detailed usage estimates for energy consumption, two questions arise. First, how many different energy-consuming appliances contribute to household electricity load, and secondly which appliances? Using national average penetration rates, the Residential Energy Consumption Survey (RECS), estimates that 42 unique appliances account for 93% of electricity consumption, while 12 appliances account for 80% of average household electric load. A typical scenario is developed from national and regional penetration rates and find that eight appliances are responsible for 80% of a household's electric load in the United States. Four household scenarios are developed: a house that uses electric appliances, gas appliances, the average household, and typical household. It is concluded that RECS cannot be used as a representative household as it overestimates the number of appliances that contribute to a household electric load. The number of significant appliances is affected by appliance ownership and use, which is more variable between homes than between census divisions. These results can be used to design and maximize the value of residential energy information and management systems.

A drifting impact oscillator with periodic impulsive loading: Application to percussive drilling

Percussive drilling is extensively used to drill hard rocks in the earth resource industry, where it performs best compared to other drilling technologies. In this paper, we propose a novel model of the process that consists of a drifting oscillator under impulsive loading coupled with a bilinear force/penetration interface law, together with a kinetic energy threshold for continuous bit penetration. Following the formulation of the model, we analyze its steady-state response and show that there exists a parallel between theoretical and experimental predictions, as both exhibit a maximum of the average penetration rate with respect to the vertical load on bit. In addition, the existence of complex long-term dynamics with the coexistence of periodic solutions in certain parameter ranges is demonstrated.

An Innovative Approach for Pore Pressure Prediction and Drilling Optimization in an Abnormally Subpressured Basin

Summary Thus far, an indirect generalized method to predict pore pressure under subpressured conditions has not been reported in the literature. In this work, an innovative procedure is presented for estimation of pore pressure and optimization of wells drilled in the abnormally subpressured Deep Basin of the Western Canada Sedimentary Basin (WCSB). The procedure starts with detailed evaluation of five wells drilled in a township that covers the study area. Pore pressure was calculated from sonic logs and the modified D exponent by the use of Eaton's method (Eaton 1975), which proved to be the most effective approach for abnormally subpressured conditions over a variety of methods tested (Contreras et al. 2011). The optimization procedure was carried out by use of the apparent-rock-strength log (ARSL), which is an effective indicator of formation drillability and is very sensitive to the pore pressure. Next, optimization of individual sections in each well was carried out to determine the optimum types of bits and operational parameters for the lowest cost of drilling. An artificial-intelligence function was implemented to set up the optimum combination of parameters in such a way that the rate of penetration (ROP) (m/h) was increased after a number of simulation runs while controlling the bit wear. Special attention was focused on tight gas reservoirs for selection of the most suitable parameters that increase the quality of drill cuttings. It was concluded that the roller-cone bit IADC 547 (with at least 0.73 hp in the bit per square inch) provides the best-quality cuttings for the Nikanassin Group. This is of paramount importance for increasing accuracy in the quantitative determination of permeability and porosity from cuttings particularly in those tight gas reservoirs where the amount of cores is very limited. It is concluded that wells in the Deep Basin of the WCSB can be drilled efficiently with seven bit runs while maintaining the cuttings quality, bit-wear level, and well stability at a significantly high average ROP of 13 m/h. Another conclusion is that the normal trend methods from sonic logs are the most effective approach when dealing with an abnormally subpressured basin.

The 2012 John Charnley Award: Clinical Multicenter Studies of the Wear Performance of Highly Crosslinked Remelted Polyethylene in THA

Highly crosslinked polyethylene (HXLPE) in THA was developed to reduce particle-induced periprosthetic osteolysis. A series of clinical studies were initiated to determine the clinical efficacy as judged by patient-reported scores, radiographic osteolysis, and wear analysis of one form of HXLPE. The purposes of this series of studies were to (1) determine the wear rates of one form of HXLPE; (2) report long-term (7-10years) patient-reported outcome measures; (3) assess the effect of femoral head size on wear; and (4) determine the incidence of periprosthetic osteolysis. A single-center and two multicenter studies were conducted on 768 primary patients (head size 26-36mm) undergoing THA at eight medical centers. Patient-reported outcome scores, radiographic grading for osteolysis, and radiographic wear evaluation were performed. Serial plain radiographs showed no periprosthetic osteolysis in the three studies. The average femoral head penetration rates did not correlate with time in vivo for patients with standard femoral head sizes. Although there was an indication of higher wear in patients with 36-mm diameter femoral heads, it was below the threshold for producing osteolysis. The introduction of this HXLPE substantially improved the prognosis of patients after THA up to 13years as judged by clinical scores, incidence of osteolysis, and polyethylene wear measurements. Level III, therapeutic study. See the Guideline for Authors for a complete description of levels of evidence.

A Novel Tool To Improve the Rate of Penetration–Hydraulic-Pulsed Cavitating-Jet Generator

Summary On the basis of the analysis of the jet-modulating mechanism, a novel tool—a hydraulic-pulsed cavitating-jet generator (HPCJG)— is designed to further improve the rate of penetration (ROP). The HPCJG combines the advantages of a pulsed jet and a cavitating jet. When the drilling fluid flows through this tool, the fluid will be modulated to the pulsed and cavitating jet by application of the impellers and by entering into the self-resonant chamber. During this process, a pulsed cavitating jet is formed at the outlet of the bit nozzle. Because of jet pulsation, cavitating erosion, and the local negative-pressure effect, the cleaning efficiency of the well-bottom cuttings and the ROP will be improved. Laboratory and oilfield tests have indicated that the pulsed-pressure amplitude and the pressure drop of the generator increase with the increase of the flow rate. However, the frequency of the pressure pulsation is invariable in this process. This generator has been applied to more than 100 wells in eight oil fields throughout China. The results show that the maximum density of the test drilling fluid is 1.93 g/cm3, the maximum test-well depth is 6162 m, and the operation time of the generator is more than 230 hours (the maximum operation time recorded was more than 520 hours). Furthermore, the average ROP was increased by approximately 16.7% to 104.4%. In conclusion, the generator has the characteristics of a simple structure, has a long lifetime, is able to adapt well with existing drilling equipment, and can provide a safe and efficient drilling technique for deep wells.

Rock mechanics characteristic of complex formation and faster drilling techniques in Western South China Sea oilfields

In order to increase the rate of penetration (ROP) and to reduce cost, we tested detritus for mineral components to study the lithological characters of the deep-sea complex formation of Western South China Sea oilfields. The prediction models of rock mechanics parameters were established based on the experiments results of the uniaxial compressive strength (UCS), drillability, hardness, plasticity and abrasivity tests of cores sampled from the complex formation. We plotted profiles of rock mechanics parameters of 30 wells and three dimensional (3D) drillability planes using the log data to reveal the complex formations distribution and their rock mechanical properties. Then, the rock breaking mechanism of complex formation of cone and PDC bit are studied. According to rock mechanics characteristic of complex formation and adjacent well drilling data, we recommend the bit structure, drilling methods and drilling parameters for the northern Gulf Basin (NGB) and Pearl River Mouth Basin (PRMB) oilfields. The research results are used to guide the drilling work of Z-10-9-1 and Z-11-1-8AS1 well in the NGB and C-14-2-1 well in the PRMB, compared with the adjacent wells, the average drilling footage and ROP increase by 98% and 117.8%, respectively.

Femoral Head Size of 36 mm against Highly Cross-linked Polyethylene in Patients Younger than 60 Years: Minimun Three Years of Follow Up

Purpose: The purpose of this study was to evaluate the early results of total hip arthroplasty (THA) performed using large diameter femoral head against with highly cross-linked polyethylene as a bearing surface in patients less than sixty years of age. Materials and Methods: Seventy patients were enrolled and retrospectively reviewed. The mean age of patients at index surgery was 49 years and the mean follow-up period was 61 months. Clinical follow-up involved implementing the Harris hip score (HHS) and a radiographic evaluation that included linear radiolucency, osteolysis, and loosening. An annual wear rate was performed at 6 weeks; at 3, 6, and 12 months; and on a yearly basis thereafter. Results: The average HHS at last follow-up was 94 (range: 82-98). Radiographically, no osteolysis in the pelvis or proximal femur was observed in any patient. No acetabular cup or femoral stem failed due to aseptic loosening. No eccentric wear was observed on any liner, and no liner fracture occurred. However, one patient experienced hip dislocation. The average femoral head penetration rate during the fi postoperative year was 0.077±0.026 mm/year, and the average steady-state wear rate was 0.033±0.023 mm/year. Conclusion: THA with a large diameter femoral head of highly cross-linked polyethylene in patients younger than 60 years of age was found to produce results comparable to previous in vitro laboratory hip simulation studies. In particular, patient satisfaction was high due to no limitation in range of motion or hip posture during the early post-operative period. Longer-term follow-up is required to demonstrate the clinical benefi ts of this new material more comprehensively.

Candidate List Reduction Based on the Analysis of Fingerprint Indexing Scores

This correspondence proposes new candidate list reduction criteria for fingerprint indexing approaches. The basic idea is that, given a query fingerprint, the initial set of scores produced by an indexer could contain useful information to reduce the candidate list. Novel reduction criteria have been proposed, and extensive experiments have been carried out over five publicly available benchmarks, using two state-of-the-art fingerprint indexing techniques. Although quite simple, the proposed criteria achieved remarkable results, allowing a substantial reduction of the candidate list: for instance, at 1% error rate, the average penetration rate of a state-of-the-art minutiae-based indexer decreases from 27% to 3.9% on FVC2000 DB2. The new reduction criteria are applicable to any indexing approach, since they only require a list of scores as input.

Influence of penetration enhancers on in vitro transdermal permeation of L-tethrahydropalmatine

To study the effect of different penetration enhancers on the in vitro transdermal permeation of 1-tethrahydropalmatine (L-THP) through rat skin. Both natural and chemical synthesis penetration enhancers were applied singly or jointly to investigate the skin permeation rates of l-THP. The skin permeation profiles were evaluated by Valian-Chien permeation cells with isolated rat skin. HPLC-UV method was established to determine the concentration of l-THP in samples. As chemical synthesis penetration enhancer was used alone, 8% azone was observed to be the optimal penetration enhancer with the maximal penetration rate of 21.153 microg x cm(-20 x h(-1). Although 2% menthol crystal or 5% eucalyptus oil was effective as a natural penetration enhancer when used alone, the average penetration rate reached only half of that of 8% azone. The penetration potency of either menthol oil or menthol crystal combined with 8% azone was more effective than that of azone alone (P < 0.05). Either menthol oil or menthol crystal combined with 8% azone is effective on transdermal penetration of l-THP in vitro. There is significant synergistic effect when natural penetration enhancers combined with chemical synthesis penetration enhancers.

Comparison of Empirical Model for Penetration Rate Prediction using Case History of TBM Construction

This paper describes prediction results of penetration rate using case history in order to compare empirical models for penetration rate prediction of TBM. The reasonable empirical model is evaluated by comparison with prediction results and measured result. The penetration rate prediction is applied in separate empirical models considering rock characteristics and mechanical characteristics of TBM. The rock of applied filed had almost gneiss and its unconfined compressive strength was irregular due to the exist of weak zones and joint. In prediction results using unconfined compressive strength, Graham's model (1976) had impractical result when it had lower strength. NTNU model (1998) of the separate empirical models used in average penetration rate had the highest accuracy by comparison with the others, because it is a reasonable model which has rock characteristics and mechanical characteristics of TBM. However, Tarkoy's model (1986) based on unconfined compressive strength correspond with the measured values in field. Therefore, it should be considered a rock type, geological characteristic and mechanical characteristic of TBM at prediction of penetration rate.

Improved Drilling Efficiency Technique Using Integrated PDM and PDC Bit Parameters

Summary In this paper, a new drilling optimization procedure is presented that is designed to improve the drilling efficiency with positive displacement motors (PDMs) and PDC bits. This developed optimization method is based on predicting rate of penetration (ROP) from PDM outputs for any PDC bit design. More specifically, optimization is done for a hole section and optimum values of weight on bit (WOB) and surface RPM are obtained for the section. For given flow rates, estimated values of optimum WOB and surface RPM are used to calculate the corresponding motor differential pressures and the foot by foot ROP values. Also, the method is used to show how improper operational parameter selection can affect total drilling time. A case study was done to consider different PDMs with different lobe configurations and a set of fixed operational parameters. The presented method is verified by generating a confined rock strength log based on drilling data for a previously drilled well in Alberta. This foot-by-foot strength log is compared to a confined rock strength log generated as a follow-up analysis by a commercially available drilling simulator package. Also, a PDM differential pressure log is generated and compared to field-recorded on-bottom differential pressure values. The method's application is best demonstrated by simulating the drilling operation of the Alberta well with three different PDMs. It is shown that consideration of PDM performance/selection in the drilling planning phase will help to perform a safe and cost-effective operation by preventing motor stalls and maintaining highest average ROP for the section. It is also shown that by optimizing WOB and surface RPM values for a constant mud flow rate and predefined bit wear at total depth, a maximum average ROP for the section can be reached for any PDM.