Physicochemical characteristics of oil-based cuttings from pretreatment in shale gas well sites.

Understanding the physicochemical characteristics of oil-based cuttings (OBCs) is an important foundation for subsequent treatment and management. The macro- and microscopic properties of white oil-based cuttings (WOBCs) and diesel-based cuttings (DBCs) after the different pretreatment steps have been assessed using scanning electron microscopy. The organic and inorganic compositions of OBCs have been analyzed using X-ray diffraction, Fourier-transform infrared spectrometry, and gas chromatography-mass spectrometry. Inorganic matter (SiO2, BaSO4, and CaCO3), alkanes, aromatic compounds, and water were the main components of OBCs. The organic content (26.14%) and alkane content of the WOBCs were higher than that of the DBCs, whereas for the inorganic content (70.87%), the reverse was true. The macro- and micromorphologies of OBCs were quite different because their oil and water contents were different. The oil contents of OBCs decreased in the order A1 (14.64%) > A3 (12.67%) > A2 (11.06%) and B1 (9.19%) > B3 (8.94%) > B2 (4.66%); the water contents decreased in the order A1 (2.99%) > A3 (2.19%) > A2 (1.09%) and B1 (2.30%) > B3 (1.87%) > B2 (1.09%). Moreover, a skid-mounted treatment technology for OBCs was proposed. The results can be a scientific guidance for the treatment and management of OBCs.

Research on the influencing factors and mechanism of single-phase microemulsion cleaning of shale gas oil-based cuttings.

Oil-based cuttings (OBCs) produced by shale gas exploitation are classified as hazardous waste. Their appropriate utilization and disposal is a key issue that urgently needs to be resolved. A single-phase microemulsion (SPM) has ultra-low interfacial tension and strong solubilization ability. In view of this, based on an analysis of the characteristics of OBCs, SPMs have been selected for their cleaning. The effects of microemulsion components and other conditions on the cleaning efficacy have been explored, as well as the deoiling mechanism and the recycling efficiency of the SPM. Our results have shown that sodium dodecylbenzene sulfonate (SDBS), n-butanol, water, and white oil in appropriate proportions can form an effective SPM. The oil content (OC) of OBCs after cleaning was reduced from 11.89% (±0.32%) to 1.13% (±0.02%) when the proportions of the aforementioned components of the SPM were 14.3%, 14.3%, 66.6%, and 4.8%, respectively. The OC of the residue further decreased to 0.28% (±0.05%) after a second cleaning with an alkaline solution. The optimum SPM conditions for cleaning OBCs were identified as a stirring speed of 200 rpm, a temperature of 30 °C, a cleaning time of 30 min, and a solid to liquid mass to volume ratio of 1:4. The main mechanism whereby the SPM cleans the OBCs is that the former reduces the combined work and adhesion work required for the removal of oil droplets from the cuttings, so that the adhesive oil is easily gathered up. Furthermore, the gathered oil phase is solubilized by the SPM.

Precise hepatectomy based on the optimized technique of hepatic blood flow occlusion combined with the curettage and cut technique by electrotome.

BACKGROUND: The aim of this study was to evaluate the outcome of precise hepatectomy based on the optimized technique of hepatic blood flow occlusion combined with the curettage and cut technique by electrotome. METHODS: Hospitalized patients with primary liver cancer treated in our hospital were included in this study and all patients (N.=61) were numbered according to the inclusion sequence and were randomized into group A and group B: 1) group A: precise liver resection by using simplified blocking combining with electrotome; 2) group B: precise liver resection by using half-hepatic occlusion + CUSA assisting liver parenchyma transection+ lower central venous pressure controlled by the anesthesiologist. Postoperative laboratory examination data (blood routine, liver function, renal function, blood coagulation function, AFP quantitation) were collected, including WBC, alanine aminotransferase (ALT), total bilirubin (TBIL), prothrombin time (PT), creatinine (Cr), abdominal drainage volume, intra-abdominal hemorrhage, bile leakage, blood transfusion, time of postoperative passage of gas by anus, and length between postoperation and discharge. RESULTS: Five days postsurgery, the value of WBC between groups A and B were not significant different (8.9±2.2 vs. 8.3±2.8, P>0.05). The ALT, PT, Cr, abdominal drainage volume, abdominal drainage volume, intra-abdominal hemorrhage, bile leakage, blood transfusion, and time of postoperative passage of gas by anus between group A and B were not significant different postoperatively, respectively. And also, the length between postoperation and discharge were not significant different between two groups. CONCLUSIONS: Precise hepatectomy based on the optimized technique of hepatic blood flow occlusion combined with the curettage and cut technique by electrotome works well. This technology has a low requirement for hospital's operation condition and anesthetist, so it carries out a new route for the wide application of precise liver resection in basal hospitals.