GMAC: A Geant4-based Monte Carlo Automated computational platform for developing nuclear tool digital twins.

Nuclear technology is widely used for hydrocarbon exploration by deploying nuclear tools of detection to help obtain important parameters of a given geographical formation. Monte Carlo software is generally used to simulate nuclear tools in the environment of well logging, to accurately predict their responses downhole. In other words, a digital Monte Carlo twin of the designated tool is constructed, and its responses, are used to identify features that are important, for instance, for assessing the feasibility of deployment of the tool or optimizing the design of its hardware. However, the downhole environment is complex and changeable, such that it is determined by many parameters, e.g., the formation, the fluid, and the structure of the well. A significant modeling setup is thus often required to be able to consider all environmental variations, where this increases the burden on field engineers who need to construct several batches of repetitive models to simulate the same tool in a variety of environments. The appropriate automation of this process is thus highly desirable. In this work, the authors propose downhole Geant4-based Monte Carlo Automated Computational Platform (GMAC) to develop digital twins of nuclear tools. We construct a platform that enables us to design a Monte Carlo digital twin of a given nuclear tool. GMAC can automate the process of simulating the tool under various environments based on minimum user input and provide a comprehensive evaluation of its performance. The proposed platform also provides feasible means to optimize the tool by connecting the CAE twin directly to the Monte Carlo twin. The main structure and developer/user functions of the GMAC are discussed in detail. Three examples of nuclear tools are also provided to detail and verify its complete process from tool design to application. The results confirm the correctness and efficiency of the proposed computational platform.

New development of sensitivity improvement for compensated neutron porosity tool in gas-filled boreholes.

Porosity is one of the most important indicators used for hydrocarbon reservoir evaluation and extraction. However, obtain accurate formation porosity measurements in gas-filled boreholes can be challenging, this is because gas cannot slow down neutrons as effectively as water due to its lower hydrogen index, which results in measurement sensitivity reduction and consequently impacts the obtained porosity. One way to address this issue is loading water into the borehole which is commonly referred to as water loading. However, this process significantly increases operational time and cost, as well as shielding perforated gas zones. Therefore, a new strategy is proposed to improve the sensitivity of porosity measurement in gas or air-filled boreholes without the need for water loading. The key to this strategy is to incorporate a sleeve design outside the tool to enhance its performance in gas-filled intervals. The sleeve is composed of a downhole applicable material whose neutron slowing down ability is close to water. The optimized deployment orientation of the sleeve could then be determined through simulation. In this work, three potential sleeve materials are identified and compared based on an existing neutron porosity tool. The impacts of different tool-sleeve-borehole orientations are analyzed to determine the most effective design strategy. A series of test pit experiments is conducted to validate the feasibility of the design.

Trace element bioavailability, yield and seed quality of rapeseed (Brassica napus L.) modulated by biochar incorporation into a contaminated technosol.

BACKGROUND AND AIMS: Rapeseed (Brassica napus L.) is a Cd/Zn-accumulator whereas soil conditioners such as biochars may immobilize trace elements. These potentially complementary soil remediation options were trialed, singly and in combination, in a pot experiment with a metal(loid)-contaminated technosol. METHODS: The technosol [total content in mg kg(-1) Zn 6089, Cd 9.4, Cu 110, and Pb 956] was either amended (2% w/w) or not with a poultry manure-derived biochar. Rapeseed was cultivated for both soil treatments during 24 weeks up to harvest under controlled conditions. RESULTS: Biochar incorporation into the technosol promoted the As, Cd, Cu, Mo, Ni, Pb and Zn solubility. It decreased foliar B, Cu and Mo concentrations, and Mo concentration in stems, pericarps and seeds. But, it did not impact neither the biomass of aerial rapeseed parts (except a decrease for seeds), nor their C (except a decrease for stems), seed fatty acid, seed starch and soluble sugar contents, and antioxidant capacity in both leaves and seeds. Biochar amendment increased the phytoextraction by aerial plant parts for K, P, and S, reduced it for N, Ca, B, Mo, Ni and Se, whereas it remained steady for Mg, Zn, Fe, Mn, Cu, Cd and Co. CONCLUSIONS: The biochar incorporation into this technosol did not promote Cd, Cu and Zn phytoextraction by rapeseed and its potential oilseed production, but increased the solubility of several metal(loid)s. Here Zn and Cd concentrations in the soil pore water were decreased by rapeseed, showing the feasibility to strip available soil Zn and Cd in combination with seed production.

[Diagnosis realization of knee joint synovial chondromatosis:clinical data of 28 cases].

OBJECTIVE: To investigate diagnosis and therapeutic effects of knee joint synovial chondromatosis with arthroscopic. METHODS: From March 1995 to July 2011, 28 patients with knee joint synovial chondromatosis were treated. Among them, 18 males and 10 females ranging age from 25 to 81 (mean 55.2) years,the course of disease ranged from 0.5 to 15 (mean 5.6) years. Clinical manifestation mainly included pain, swell and functional limitation of knee joint. Knee open surgery (17 cases) and laparoscopic surgery (10 cases) were respectively used. Clinical symptom,image data,pathological manifestation and effects under arthroscopy were observed, Lysholm scoring was used to evaluate effects. RESULTS: All patients were followed up except one lost, the duration ranging from 6 to 24 months. Lysholm score in knee open surgery was increased from (41.89 +/- 6.81) preoperatively to (67.73 +/- 7.62) postoperatively;while in laparoscopic surgery it was increased from (40.78 +/- 7.54) preoperatively to (77.46 +/- 8.43) postoperatively. CONCLUSION: Arthroscopic surgery, which has no risk of rupture of incision, nonunion, earlier to exercise, is a good method to diagnosis and treat knee joint synovial chondromatosis.