Simulation Studies on the Effect of Asphaltene Precipitation on Oil Recovery during CO₂ Injection for Light Oil Reservoir

Enhanced Oil Recovery (EOR) is method widely use in many company for production. Gas injection is one of the oldest and most popular methods used in EOR. EOR is used to increase oil recovery. Gas is injected inside the reservoir and is stored in the geological formation. CO2 injection is one type of gas injection and is preferred to use in light oil reservoir as the gas and oil can be mix forming a miscible phase reducing the interfacial tension of crude oil and flowing together to the surface. Unfortunately, in wells that has asphaltene, precipitation tends to exist even though the percentage of asphaltene is small. Once precipitation occurs, the asphaltene will clump together forming a flock of asphaltene and deposit in the reservoir when it is too heavy to be carried out by the flow causing formation damage such as porosity and permeability reduction and wettability alteration. Asphaltene precipitation will also cause the wellbore, tubing and facilities equipments to break down due to the accumulation in it. All these will lead to decrease in production. The author will continue doing research work reading more to understand the effect of asphaltene. Then, the author will use CMG software to simulate light oil reservoir under CO2 injection to anticipate the outcome before it actually happens as when precipitation occurs, the cost to clean it mechanically and chemically is time consuming, expensive and unsafe. The author will use the Builder, WinProp and GEM to do the simulation work. The findings that the author found was consistent which the experimental work done by many experts in the industry and the author had proven that asphaltene precipitation causes formation damaged which in turn reduces the permeability and porosity of the formation

End-of-life vehicle (ELV) recycling management: improving performance using an ISM approach

With booming of the automobile industry, China has become the country with increasing car ownership all over the world. However, the end-of-life vehicle (ELV) recycling industry is at infancy, and there is little systematic review on ELV recycling management, as well as low adoption amongst domestic automobile industry. This study presents a literature review and an interpretive structural modeling (ISM) approach is employed to identify the drivers towards Chinese ELV recycling business from government, recycling organizations and consumer’s perspectives, so as to improve the sustainability of automobile supply chain by providing some strategic insights. The results derived from the ISM analysis manifest that regulations on auto-factory, disassembly technique, and value mining of recycling business are the essential ingredients. It is most effective and efficient to promote ELV recycling business by improving these attributes, also the driving and dependence power analysis are deemed to provide guidance on performance improvement of ELV recycling in the Chinese market

Simulation Studies on the Effect of Asphaltene Precipitation on Oil Recovery during CO₂ Injection for Light Oil Reservoir

Enhanced Oil Recovery (EOR) is method widely use in many company for production. Gas injection is one of the oldest and most popular methods used in EOR. EOR is used to increase oil recovery. Gas is injected inside the reservoir and is stored in the geological formation. CO2 injection is one type of gas injection and is preferred to use in light oil reservoir as the gas and oil can be mix forming a miscible phase reducing the interfacial tension of crude oil and flowing together to the surface. Unfortunately, in wells that has asphaltene, precipitation tends to exist even though the percentage of asphaltene is small. Once precipitation occurs, the asphaltene will clump together forming a flock of asphaltene and deposit in the reservoir when it is too heavy to be carried out by the flow causing formation damage such as porosity and permeability reduction and wettability alteration. Asphaltene precipitation will also cause the wellbore, tubing and facilities equipments to break down due to the accumulation in it. All these will lead to decrease in production. The author will continue doing research work reading more to understand the effect of asphaltene. Then, the author will use CMG software to simulate light oil reservoir under CO2 injection to anticipate the outcome before it actually happens as when precipitation occurs, the cost to clean it mechanically and chemically is time consuming, expensive and unsafe. The author will use the Builder, WinProp and GEM to do the simulation work. The findings that the author found was consistent which the experimental work done by many experts in the industry and the author had proven that asphaltene precipitation causes formation damaged which in turn reduces the permeability and porosity of the formation

Production Of Juvenile Hormone Iii (Jh Iii) From Cyperus Aromaticus Via Cell Suspension Culture Technique And Its Effect On Mosquito Larva, Aedes Aegypti

Callus of Cyperus aromaticus was induced from the root explants using modified Murashige and Skoog (1962) medium supplemented with 5.5 mg/L NAA and 4.5 mg/L 2,4-D. Seven stable cell lines were selected from these root-derived calluses. Cell suspension cultures were then established from these selected cell lines. Optimum cell biomass and high Juvenile Hormone III (JH III) content could be produced via single stage cell culture system using a modified culture medium. JH III of the tested samples was detected with high performance liquid chromatography (HPLC). The optimum culture duration for the production of high cell biomass and JH III content was 12 days. The optimized culture medium was formulated via step-wise modification of macronutrients portion of the basic MS medium and plant growth regulators. All the selected cell lines grew well in this optimum medium which consisted of MS supplemented with 271.1 mM NH4NO3 + 15.4 mM KNO3 + 4.3 mM CaCl2.2H2O + 1.49 mM MgSO4.4H2O + 1.35 mM KH2PO4 + 3% sucrose + 5.5 mg/L NAA + 4.5 mg/L 2,4-D (MSB) medium

Study of Relationship Between Performance (ROA) And Internal And External Factors On Axiata Group Berhad

The purpose of this study is to examine the relationship between the various variables that include internal factors and external factors and the overall performance of Axiata Group Berhad. The measurement of return on assets is used to see the overall performance of Axiata Group Berhad in 5 years. The additional measurements that used in this study are total asset size and remuneration of board, these variables used to measure whether there is significant to the performance of the company. For the purpose to measure the relationship of risks factors to the profitability, this paper is using liquidity risk, market risk, leverage risk, GDP, inflation rate, unemployment rate and exchange rate. Data was analyzed by SPSS System which interpret the data by using descriptive statistic, correlation and regression analysis. The result of these analysis show only one factor is significant to performance of the group which is debt to equity ratio with the highest significant to the profitability. However, the inflation rate and GDP is insignificant to profitability

Huge adenomyotic cyst in pregnancy

Adenomyotic cyst is a rare variant of adenomyosis. It is believed to arise from repeated focal haemorrhages resulting in cystic spaces filled with altered blood products. We present a rare case of a huge adenomyotic cyst in a 27-year-old primigravida, who was in her first trimester, complaining of sudden lower abdominal pain. Diagnostic laparoscopy performed to rule out other cause of acute abdomen. Her pregnancy went on smoothly. She delivered a baby girl of 2.82 kg via vaginal delivery at 39 weeks. Diagnosis and management of this rare clinical entity were reviewed and discussed

Urethral masson’s tumour: a rare and puzzling entity

Intravascular papillary endothelial hyperplasia (IPEH) or Masson’s tumour is a benign vascular proliferation that mimics other malignant vascular tumour. To date, this is the fourth case of Masson’s tumour at urethra being reported in the literature. A 65-year-old female Para 2, presented with post-menopausal bleeding. Examination revealed a 4x3x3 cm growth surrounding the urethral meatus. She underwent examination under anaesthesia and excision of the periurethral mass. Histopathological examination confirmed Masson’s tumour. Diagnosis and management of this uncommon tumour at a rare location was discussed

Successful fault current interruption on DC circuit breaker

This study focus on the interruption capability of the DC circuit breaker employing a current commutation approach and evaluates the two main factors that determine the success rate for breaker current interruption, namely the current slope di/dt before current zero and the rate of rise of the transient recovery voltage dv/dt across the mechanical breaker contacts after current zero. A vacuum circuit breaker is used to evaluate DC breaker characteristics. Detailed mathematical and graphical analysis are presented for the proposed circuit operation used in analysing the circuit breaker properties, with simulation and experimental results at fault current levels up to 330 A

Velamentous cord insertion: a rare cause of emergency caesarean section

Pregnancies complicated with velamentous cord insertion (VCI) are at risk of adverse perinatal outcome. Placental and umbilical cord assessment should be performed during routine obstetric ultrasound. We report a case of velamentous cord insertion that was not identified antenatally. A 28-year-old primigravida at 40 weeks gestation presented in active phase of labour. Intrapartum, cardiotocography (CTG) tracing was pathological. Thus, decision was made for emergency caesarean section and a velamentous cord insertion was found. Despite a favourable outcome, this case highlighted the importance of antenatal diagnosis of VCI and thus preventing catastrophic outcome