Water cut forecast after downhole pumping equipment optimization based on displacement characteristics

The article deals with the issue of water cut predicting when downhole pumping equipment optimizing. In practice, an expert assessment of this parameter is used as a rule, which does not take into account the degree of planned optimization relative to the current mode. The paper proposes a methodology allowing taking into account the dynamics of planned fluid withdrawals in predicting water cut based on displacement characteristics. To solve the described problem, four characteristics were selected with a certain type of statistical dependence, where, in one part of the equation, fluid withdrawals do not depend on oil withdrawals. This allows, by setting different values of fluid production, to predict oil production and water cut at any time period. On the example of deposits of one of the regions of the Ural-Volga region, the most suitable for certain geological conditions displacement characteristics were determined. Look back analysis shows a high degree of convergence between the calculated and actual water cut indicators – the average absolute deviation is 1.9%, which allows forecasting with sufficient accuracy. Keywords: oil fields development; production stimulation; displacement characteristics; water cut.

Back Analysis of a Horizontal Geothermal Plant Implemented in a Wine Production Process

The Salcheto winery has undertaken a process of reduction of its primary energy consumption and the implementation of green energy technologies. They adopted solar photovoltaic, wood biomass, and geothermal energy sources. A horizontal ground source heat exchanger (GSHE) plant is used to cool a part of the pressed grapes and control the wine production temperature. The goal of this work was to investigate some technical issues of the plant and to increase the efficiency of the whole system. The first step was the evaluation of the actual operating conditions of the GSHE plant, by performing a thermal response test. The results allowed us to find the thermal diffusivity of 3.5 × 10−7 m2/s, and the calculation with the IGSHPA standard indicated a cooling performance of about 6 kW. A survey during the harvest highlighted a peak power of 6 kW. Therefore, to improve the plant, some modifications were proposed and analyzed. In the new layout, the geothermal plant serves the condenser of the refrigeration unit, allowing cooling of the all production lines, instead of only one. The peak power was evaluated as 32 kW, and the GSHE can fulfil this, up to 18 kW. For higher power, the evaporative tower will supply the remainder, covering a maximum of 45%. Furthermore, the refrigeration unit may cover the cooling requirements of the entire residential and office building, without other plant improvements.

Experimental study on load sharing characteristics of long-short CFG pile composite foundation adjacent to rigid retaining wall rotating about its base

Practicing geoengineers and researchers generally consider the load sharing behavior in multi-type pile composite foundation as an important design aspect. On the other hand, due to urbanization, such foundation system in cities will inevitably appear next to supported excavation. This paper discusses the result from relatively large-scale indoor experiment conducted to investigate the load sharing behavior of loaded long-short CFG pile composite foundation behind a neighboring rigid retaining wall undergoing rotation around the bottom. It was found that with progression of wall movement, the hidden load from soil displacement was borne by the piles with marked reduction in soil load sharing. At the end of wall rotation, the percentage of long piles’ head load increment needed to arrive at a new static equilibrium was about 12.57~32.22% while the end bearing increased by more than 97%. The consequences on the short piles, however, were manifested with an increasing pile head (13.42%) and toe (28.9%) load for the pile far from the wall whereas the closest one experienced a certain increment up to 15×10-4rad wall rotation and finally the head load and end bearing decreased to 8.28% and 12.63%, respectively. The 3D numerical back analysis conducted using FE software ABAQUS yielded the pile – soil stress ratio lower than the value obtained from the experiment but provided great insight into pile settlement characteristics during wall rotation.

Strength of Chemically Stabilized Sewage Sludge—Some Inferences from Recent Studies

Although there has been a substantial body of research on the chemical stabilization of sewage sludge, most of these results are project-specific and relate mainly to the use of new binders and sewage sludge from specific sources. In this sense, much of the work to date is context-specific. At present, there is still no general framework for estimating the strength of the chemically treated sludge. This paper proposes one such general framework, based on data from some recent studies. An in-depth re-interpretation of the data is first conducted, leading to the observation that sludge, which has coarse, hard particulate inclusions, such as sand, premixed into it, gives significantly higher strength. This was attributed to the hard coarse particles that lower the void ratio of treated soil, are much less susceptible to volume collapse under pressure, and contribute to the strength through frictional contacts and interlocking. This motivates the postulation of a general framework, based on the premise that coarse, hard particulate inclusions in the sludge which do not react with the binders can nonetheless contribute to the strength of the treated soil. The overall void ratio, defined as the volume of voids in the cementitious matrix normalised by the overall volume, is proposed as a parameter for quantifying the combined effect of the coarse particulate inclusions and the cementitious matrix. The binder-sludge ratio is another parameter which quantifies the strength of the cementitious matrix, excluding the hard particulate inclusions. Back-analysis of the data suggests that the significance of the binder-sludge ratio may diminish as the content of hard particulate inclusions increases.

Investigations of a Weathered and Closely Jointed Rock Slope Failure Using Back Analyses

This study presents the case of a landslide triggered by a high groundwater level caused by several days of continuous rainfall in the northeastern region of Taiwan. The slope where this landslide occurred consists of closely jointed and weathered bedrock. By means of finite element limit analysis and the Hoek–Brown failure criterion, this study performed a slope failure simulation similar to the actual landslide and deduced the reasonable value range for the combination of key Hoek–Brown failure criterion parameters through back analyses. The results indicate that the key parameters affecting the bedrock’s slope stability were the geological strength index (GSI) and the disturbance factor (D), whereas the effects of the unconfined compressive strength (σci) were less significant. The results of the back analysis reveal that the suitable D-value range and GSI of closely jointed and weathered sandstone in the northeastern region of Taiwan are 0.8 to 0.9 and 20 to 30, respectively. These back-analyzed value ranges can serve as a reference for broader applications in the preliminary stability analysis of similar rock slopes where it is difficult to perform in situ investigation.

Correlations of geotechnical monitoring data in open pit slope back-analysis -A mine case study

Geotechnical monitoring plays an important role in the detection of operational safety issues in the slopes of open pits. Currently, monitoring companies offer several solutions involving robust technologies that boast highly reliable data and the ability to control risky conditions. The monitoring data must be processed and analysed so as to allow the results to be used for several purposes, thereby providing information that can be used to manage operational actions and optimize mining plans or engineering projects. In this work we analysed monitoring data (pore pressure and displacement) and its correlation with the tension and displacement of the mass of an established failure slope calculated using the finite element method. To optimize the back-analysis, a Python language routine was developed using input data (point coordinates, parameter matrix, and critical section) to use software with the rock mass parameters (cohesion, friction angle, Young's modulus, and Poisson's ratio). For the back-analysis, the Mohr-Coulomb criterion was applied with the shear strength reduction technique to obtain the strength reduction factor. The results were consistent with both the measured displacements and the maximum deformation contours, revealing the possible failure mechanism, allowing the strength parameters to be calibrated according to the slope failure conditions, and providing information about the contribution of each variable (parameter) to the slope failure in the study area.

Study on Unloading Relaxation Characteristics of Columnar Jointed Rock Masses Based on Displacement Back Analysis

We aim to understand the relaxation of columnar joint rock masses during the excavation process of the diversion tunnel of the Baihetan hydropower station. This paper inverts the deformation parameters of the relaxed columnar joint rock based on the displacement monitoring data, and introduces a relaxation factor to describe the deterioration degree of anisotropic parameters of the relaxed columnar jointed rock. The equivalent strain is proposed as the criterion of unloading relaxation and the threshold is also given. Based on the software Flac3d, a program for calculating anisotropic elastoplastic model is developed. The distribution of the relaxation zone of the diversion tunnel after excavation is simulated, and compared with the results of the acoustic detection to verify the correctness and rationality of the program, which can provide a necessary reference for the design and construction of hydropower projects.

Use of Cryopreserved Allogeneic PBSC Results in Delayed Engraftment and Increased Incidence of Poor Graft Function

Use of Cryopreserved Allogeneic PBSC Results in Delayed Engraftment And Increased Incidence of Poor Graft Function Introduction: During COVID Pandemic, national and international transplant centres agreed to use cryopreserve the donor PBSC as a safer option to deliver allogeneic transplants. Published data suggests that use of cryopreserved allogeneic PBSC is safe and comparable to use of fresh PBSC but cryopreservation of stem cells may lead to cell loss and hence efficacy. During COVID pandemic, use of cryopreserved allogeneic PBSC was adopted as policy on 01/06/2020. This look back analysis evaluates the impact of change in policy. Aims: Evaluate Engraftment time, compare with historical data, blood component support, and use of growth factors Methods and Materials: Data was collected from health records (paper and electronic) and laboratory records. Transplant features and engraftment kinetics were analysed. Results: Group A June 2020 to November 2020, 19 patients [M: 13; F: 6; median age: 50yr (range: 23-69)] who received cryopreserved allogeneic PBSC were compared to 35 patients [M:24; F:11; median age: 59yr (range: 21-71)] receiving fresh allogeneic PBSC for engraftment kinetics. There were no differences between two groups regarding underlying diagnosis (p=0.31), sex mismatch, CMV mismatch, blood group mismatch, reduced intensity conditioning [RIC](p=0.28), type of donor (p=0.98) or use of Alemtuzumab (p=0.88). Median infused Cell dose in group A was 5.3 (3.4-7.16) and in group B 4.9 (1.03-6.85), [p=0.11]. Neutrophil engraftment was significantly faster with fresh PBSC as compared to cryopreserved PBSC (16d vs. 25d, p=0.0025) predominantly with MUD (18d vs. 27d, p=0.009) and RIC (16d vs. 25d, p=0.009). Platelet engraftment to 25 was faster with fresh PBSC (13d vs. 20d, p=0.021) with delayed engraftment in MUD (20d vs. 13d, p=0.006) and RIC (23d vs. 13d, p=0.039). Day to engraftment per unit CD34 was shorter with fresh PBSC for neutrophils (median: 3.2, range: 2.0-7.7 vs. 5.3, range: 2.5-16.7; p=0.006) and platelets (median: 2.4, range: 1.7-25 vs. 3.8, range: 2.2-25; p=0.001) but only for MUD. This suggests 35-40% less efficiency with use of cryopreserved PBSC. There was no difference in the need for transfusion support [RBCs (6 units vs. 3 units, p=0.32); platelets (5 pools vs. 7 pools, p=0.33)]. G-CSF use was higher with cryopreserved PBSC in RIC (54% vs. 20%, p=0.031). Two patients experienced TRM before day 90 (3.7%). At day 90, 17/52 (32.7%) had cytopenia in one lineage and 8/52 (16%) had cytopenia in more than one lineage. Delayed engraftment was observed in 10 of 33 patients (30.3%) transplanted in 2020 and the only significant association was use of cryopreserved PBSC (0% vs. 53%, p=0.001). There was no difference in the incidence of aGVHD, hepatic VOD, microangiopathy and bacterial infections. Numbers are not sufficient to make disease specific comparisons. Conclusion: Cryopreserved PBSC result in delayed neutrophil and platelet engraftment predominantly with MUDS and RIC. Incidence of delayed engraftment and poor graft function is higher. Per unit CD34 dose, cryopreserved PBSC are 30-40% less efficient to achieve engraftment. Delayed engraftment with cryopreserved PBSC especially in MUD raises the possibility that time from harvest to cryopreservation contributes to reduced efficacy. Based on these findings it was decided to infuse higher CD34 dose (6-7x10^6/kg as compared to usual 4-5x10^6/kg) for cryopreserved MUD PBSC. Disclosures Bloor: Kite, a Gilead Company: Honoraria; Novartis: Honoraria.