New filtration parameters from X-ray computed tomography for tight rock images

New parameters are proposed to evaluate the filtration properties of rocks obtained on the basis of 3D interpretation of images from X-ray computed tomography. The analyzed parameters are: global average pore connectivity, average blind pore connectivity, blind pore coefficient per object and blind pore coefficient per branch. The 3D pore space from computed X-ray tomography must be subjected to a process of pore space transformation into a skeleton. Then, the presented parameters can be evaluated, taking into consideration the pore channels (branches), pore channel connection points (junctions) and blind pores (pore without connection to the other pore). The calculations were made for low porosity sandstones, mudstones, limestones, and dolomites which differ in terms of age and depth of present deposition. The global average pore connectivity reflects the degree of development of the pore space in which the formation fluid can flow. The higher the global average pore connectivity, the most complex the pore structure can be expected. The higher the parameter of the average blind pore connectivity, the worse are the filtration properties of the rock. The higher the concentration of blind pore coefficient per object or branch, the worse the filtration properties of the rock. Moreover, new parameters were compared with the Euler characteristic and coordination number, revealing a high consistency

Velocity models for seismics based on well log data

Compressional (Vp) and shear (Vs) elastic waves velocities were determined from logging measurements using FWS tool and acoustic full wavetrains processing using FalaFWS application in GeoWin system. Estymacja program was used to calculate both types of wave velocities (Vp, Vs) and bulk density theoretical formulas, which combine quantities dependent on mineral composition, porosity, water saturation and type of medium in the rock. The results were compared with respect to P and S waves slowless, bulk density and dynamic elastic moduli: Young modulus, bulk modulus, shear modulus and Poisson ratio. It was determined that in the absence of Vp and Vs with a lack of acoustic full wavetrains registration, only the Estymacja program provides the expected results. The FalaFWS application broadens the range of results compared to logging results in depth sections where velocity of mud is higher than the velocity of S wave in formation

Scaling of well log data for velocity models in seismics

The results from the mathematical operations of filtration and interpolation are presented for dynamic elastic parameters such as P-wave slowness and S-wave slowness, Young modulus and Poisson ratio. The parameters were obtained by interpreting acoustic full waveforms using FalaFWS application of GeoWin system and based on calculations using the Estymacja program. The subject of the analysis were the results obtained from various lithostratigraphic formations in several Polish Lowland's borehole profiles sampled from surface to a depth of more than 5 km. The goal was to scale well log data of a high vertical resolution for seismic purposes. Average values of the elastic parameters were presented for units derived out of geological interpretation. The analysis also included calculation of the Q parameter, which is a measure of energy dispertion of elastic waves in a rock formation

Research results of triaxial geomechanical tests of a coal sample in the light of tomographic tests

The study aimed to check the possibility of using computed tomography to observe fractures in coal samples before and after a triaxial compression test (TRX). The paper presents an innovative use of two specialized laboratory techniques: computed tomography and geomechanical triaxial compression test. Geomechanical tests were performed on a TRX-070, GCTS (USA) measuring triaxial system. A full stress-strain characteristic was recorded. Also, during the triaxial compression tests, the P and S wave velocities were measured and dynamic elastic moduli were determined. The results were compared. The sample was analyzed in two stages: CT measurement performed on raw coal sample (stage 1) and after the TRX test which destroyed the sample structure (stage 2). First, the sample was scanned reflecting the initial pores and microcracks system. The final stage represents the sample after the geomechanical test. A detailed pore structure analysis was performed for each of the stages. As a result of the proposed above-mentioned method, images of the pore structure were obtained after each step. The sample was analyzed for crack propagation and changes in the pore structure. The qualitative and quantitative interpretation was based on the determination of the number of voids, crack diameters, collapse angles, and comparison of the pore structure between the initial state of the sample and after the triaxial test. In the first stage (before the test), the largest object (identified as a microcrack) had a volume of approximately 16 mm3, after the sample was stress-tested (after the sample was destroyed), the largest identified object was about 15 times larger (240 mm3). It appeared that the coal sample was prone to fracturing in defined directions. Comprehensive research has demonstrated the legitimacy of using the proposed methodology to evaluate changes in the sample structure during the triaxial test

Shale Gas in Poland

An example of interpretation of the Silurian and Ordovician shale formations in the Baltic Basin in Poland regarding determination of potential sweet spots is presented. Short geological information shows the position of shale gas play. Description of the data—laboratory measurement outcomes (petrophysical and geochemical) and well logging—presents results available for analyses. Detailed elemental analyses and various statistical classifications show the differentiation between sweet spots and adjacent formations. Elastic property modelling based on the known theoretical models and results of comprehensive interpretation of well logs is a good tool to complete information, especially in old wells. Acoustic emission investigations show additional characteristic features of shale gas rock and reveal that acoustic emission and volumetric strain of a shale sample induced by the sorption processes are lower for shale than for coals

Overall survival of patients with metastatic KRAS wild type colorectal cancer patients treated with anti-EGFR third line monotherapy

Introduction. There is no evidence-based data comparing upfront chemotherapy doublets with anti-EGFR monoclonal antibody with sequential treatment utilizing anti-EGFR monotherapy as a consecutive line of treatment in patients with metastatic colorectal cancer. Here we report real-world survival data for patients with colorectal cancer (CRC) treated with anti-EGFR monoclonal antibody as 3rd line monotherapy.  Material and methods. It was single center retrospective study. We collected retrospectively data of wild-type KRAS metastatic CRC patients who have failed oxaliplatin- and irinotecan based therapy and were treated with anti-EGFR monoclonal antibody as the 3. line monotherapy in 2009–2017 in Copernicus Memorial Hospital, Lodz, Poland. Last observation was recorded in February 2020. We calculated median overall survival (since commencement of palliative systemic treatment), median progression free survival and median OSIII (overall survival sine commencement of monotherapy with anti-EGFR agent).  Results. 130 patients were included in the study. 40,6% were females. The median age was 63 years (range 38–83). 57% of patients were initially diagnosed with metastatic/inoperable colorectal cancer. 80 patients were treated with 3. line cetuximab, 50 — with panitumumab. At the moment of data analysis 123 deaths were recorded. OS since start of palliative systemic treatment was calculated for 120 patients and its median was 25,8 months. MPFS since start of anti-EGFR antibody was 4,3 months, mOSIII —10,7 months.  Conclusions. 3rd line treatment of metastatic colorectal cancer with anti-EGFR antibodies is effective. It is good option for patients, who are not fit enough or not willing to have 1st line triplet therapy

National comparison of methods for determination of radon in water

The article describes three interlaboratory experiments concerning 222Rn determination in water samples. The fi rst two experiments were carried out with the use of artifi cial radon waters prepared by the Laboratory of Radiometric Expertise (LER), Institute of Nuclear Physics, Polish Academy of Sciences in Kraków in 2014 and 2018. The third experiment was performed using natural environment waters collected in the vicinity of the former uranium mine in Kowary in 2016. Most of the institutions performing radon in water measurements in Poland were gathered in the Polish Radon Centre Network, and they participated in the experiments. The goal of these exercises was to evaluate different measurement techniques used routinely in Polish laboratories and the laboratories’ profi ciency of radon in water measurements. In the experiment performed in 2018, the reference values of 222Rn concentration in water were calculated based on the method developed at LER. The participants’ results appeared to be worse for low radon concentration than for high radon concentrations. The conclusions drawn on that base indicated the weaknesses of the used methods and probably the sampling. The interlaboratory experiments, in term, can help to improve the participants’ skills and reliability of their results

The significant impact of age on the clinical outcomes of laparoscopic appendectomy : results from the Polish Laparoscopic Appendectomy multicenter large cohort study

Acute appendicitis (AA) is the most common surgical emergency and can occur at any age. Nearly all of the studies comparing outcomes of appendectomy between younger and older patients set cut-off point at 65 years. In this multicenter observational study, we aimed to compare laparoscopic appendectomy for AA in various groups of patients with particular interest in the elderly and very elderly in comparison to younger adults. Our multicenter observational study of 18 surgical units assessed the outcomes of 4618 laparoscopic appendectomies for AA. Patients were divided in 4 groups according to their age: Group 1- 8 days. Logistic regression models comparing perioperative results of each of the 3 oldest groups compared with the youngest one showed significant differences in odds ratios of symptoms lasting >48hours, presence of complicated appendicitis, perioperative morbidity, conversion rate, prolonged LOS (>8 days). The findings of this study confirm that the outcomes of laparoscopic approach to AA in different age groups are not the same regarding outcomes and the clinical picture. Older patients are at high risk both in the preoperative, intraoperative, and postoperative period. The differences are visible already at the age of 40 years old. Since delayed diagnosis and postponed surgery result in the development of complicated appendicitis, more effort should be placed in improving treatment patterns for the elderly and their clinical outcome

Risk factors for serious morbidity, prolonged length of stay and hospital readmission after laparoscopic appendectomy : results from Pol-LA (Polish Laparoscopic Appendectomy) multicenter large cohort study

Laparoscopic appendectomy (LA) for treatment of acute appendicitis has gained acceptance with its considerable benefits over open appendectomy. LA, however, can involve some adverse outcomes: morbidity, prolonged length of hospital stay (LOS) and hospital readmission. Identification of predictive factors may help to identify and tailor treatment for patients with higher risk of these adverse events. Our aim was to identify risk factors for serious morbidity, prolonged LOS and hospital readmission after LA. A database compiled information of patients admitted for acute appendicitis from eighteen Polish and German surgical centers. It included factors related to the patient characteristics, peri- and postoperative period. Univariate and multivariate logistic regression models were used to identify risk factors for serious perioperative complications, prolonged LOS, and hospital readmissions in acute appendicitis cases. 4618 laparoscopic appendectomy patients were included. First, although several risk factors for serious perioperative complications (C-D III-V) were found in the univariate analysis, in the multivariate model only the presence of intraoperative adverse events (OR 4.09, 95% CI 1.32-12.65, p = 0.014) and complicated appendicitis (OR 3.63, 95% CI 1.74-7.61, p = 0.001) was statistically significant. Second, prolonged LOS was associated with the presence of complicated appendicitis (OR 2.8, 95%CI: 1.53-5.12, p = 0.001), postoperative morbidity (OR 5.01, 95% CI: 2.33-10.75, p < 0.001), conversions (OR 6.48, 95% CI: 3.48-12.08, p < 0.001) and reinterventions after primary procedure (OR 8.79, 95% CI: 3.2-24.14, p < 0.001) in the multivariate model. Third, although several risk factors for hospital readmissions were found in univariate analysis, in the multivariate model only the presence of postoperative complications (OR 10.33, 95% CI: 4.27-25.00), reintervention after primary procedure (OR 5.62, 95% CI: 2.17-14.54), and LA performed by resident (OR 1.96, 95%CI: 1.03-3.70) remained significant. Laparoscopic appendectomy is a safe procedure associated with low rates of complications, prolonged LOS, and readmissions. Risk factors for these adverse events include complicated appendicitis, postoperative morbidity, conversion, and re-intervention after the primary procedure. Any occurrence of these factors during treatment should alert the healthcare team to identify the patients that require more customized treatment to minimize the risk for adverse outcomes

Research on Fluid Flow and Permeability in Low Porous Rock Sample Using Laboratory and Computational Techniques

The paper presents results of fluid flow simulation in tight rock being potentially gas-bearing formation. Core samples are under careful investigation because of the high cost of production from the well. Numerical simulations allow determining absolute permeability based on computed X-ray tomography images of the rock sample. Computational fluid dynamics (CFD) give the opportunity to use the partial slip Maxwell model for permeability calculations. A detailed 3D geometrical model of the pore space was the input data. These 3D models of the pore space were extracted from the rock sample using highly specialized software poROSE (poROus materials examination SoftwarE, AGH University of Science and Technology, Krak&oacute;w, Poland), which is the product of close cooperation of petroleum science and industry. The changes in mass flow depended on the pressure difference, and the tangential momentum accommodation coefficient was delivered and used in further quantitative analysis. The results of fluid flow simulations were combined with laboratory measurement results using a gas permeameter. It appeared that for the established parameters and proper fluid flow model (partial slip model, Tangential Momentum Accommodation Coefficient (TMAC), volumetric flow rate values), the obtained absolute permeability was similar to the permeability from the core test analysis