Evaluation of robust epoxy resin sealants for wellbore integrity applications

During the drilling and completion phases of oil and gas wells, cement is placed in the wellbore as a barrier between the casing and the formation. All casing strings must be cemented to protect and support the casing, and to isolate production zones. The primary cement must prevent the wellbore fluids from migrating in an annular flow path so as to allow the wells to be utilized without any control problems. The primary cement may fail to deliver full zonal isolation due to several reasons such as insufficient mud removal before the cementing, casing expansion, and contraction, high fluid losses, cement free fluids, inadequate hydrostatic pressure, high-pressure tests and temperature variations across the cement causing micro-annuli and cracks that may allow fluids to migrate. In addition, if the cement is placed in zones where corrosive fluids are presented, chemical degradation could compromise the cement integrity. If any of these failures occurred during the life of the well, remedial job must be performed to restore the well integrity. Failing to restore the cement integrity may lead to unwanted severe consequences to the environment, the equipment, and personnel. This work presents the results of evaluating several epoxy resin sealants that have the potential to replace the conventional Portland cement used in remedial jobs. This study includes the rheological behavior, curing kinetics, injectivity, plugging performance against water and CO2, chemical resistance, and the mechanical properties of epoxy resin sealants. This work compares the results of epoxy resin sealants to that of the conventional Portland cement. The findings obtained from this work can be utilized in optimizing the cement remedial operations --Abstract, page iv

New wellbore-integrity classification for gas migration problems and new cement formulations using Graphene Nano Platelets to prevent gas migration through cement

Gas migration, one of the primary problems related to the integrity of oil wells, is caused by cement failures. Gas migration can result in costly well repairs and may endanger personal, equipment, and result in severe operational difficulties and environmental issues. The ultimate objectives of this research were to provide a comprehensive review of the problem and to provide a solution to the problem using Graphene Nano Platelets (GNPs). An intensive review was performed to understand the cement failures. The reasons behind these failures were analyzed and classified with respect to their locations in the wellbore. Recommendations and potential solutions for these problems were also suggested. A new classification was established and would work as a roadmap to understand the oil well cement failures and would help prevent their occurrence. An intensive laboratory work was conducted to better understand the cement and the cement testing methodologies. In addition, GNPs were added to the cement to enhance its properties. The evaluation of the neat cement and the new cement formulations included testing their mineralogy by implementing X-ray diffraction (XRD) analysis, testing the mechanical properties of the set cement, testing the stability and rheology of the liquid slurry, and evaluating the chemical shrinkage of the cement. In addition, the effects of adding GNPs on the hydration process of the cement was studied using isothermal calorimeter. The findings of this investigation showed that GNPs played a key role in regulating the microstructure of the hydration products of the cement, which enhanced the toughness of the cement without affecting its stability and flow-ability. The GNPs also aided in controlling the propagation of micro cracks within the cement matrix --Abstract, page iv

Utilizing a New Eco-Friendly Drilling Mud Additive Generated from Wastes to Minimize the Use of the Conventional Chemical Additives

The cost of the drilling operation is very high. Drilling fluid presents 15 to 30% of the entire expense of the drilling process. Ordinarily, the major drilling fluids additives are viscosity modifiers, filtration control agents, and partial loss treatments. In this experimental work, full-set measurements under fresh and aged conditions, as well as high-temperature and high-pressure (HTHP) API filtration, were conducted to study the impacts of adding 0.5%, 1.5%, 2.5%, and 3.5% of black sunflower seeds’ shell powder (BSSSP) to spud mud. BSSSP of various grain sizes showed their ability to be invested for viscosity modifying, seepage loss controlling, and partial loss remediation. In addition to BSSSP eminent efficiency to be used as a multifunctional additive, the BSSSP is cheap, locally obtainable in commercial quantities, environmentally friendly additive and easy to grind into various desired grain sizes. Besides its outstanding strength to behave under conditions up to 30 h aged time and under 50 °C (122 °F) temperature, the utilization of powdered waste black sunflower shells in the drilling process and other industrial applications can reduce the effects of food waste on the environment and the personnel safety. To sum it up, experimental findings revealed that BSSSP can be used for multiple applications as a novel fibrous and particulate additive. The results elucidated BSSSP suitability in substituting or at least minimizing some of the traditional chemical materials utilized in the petroleum industry such as salt clay, polymers, and lost circulation materials (LCM)

Full-Set Measurements Dataset for a Water-Based Drilling Fluid Utilizing Biodegradable Environmentally Friendly Drilling Fluid Additives Generated from Waste

The oil and gas industry is moving towards more environmentally friendly practices. The environmental regulations regarding drilling waste management and disposal are motivating the industry to be more efficient with drilling operations. Environmentally friendly drilling fluid additives used in drilling operations reduces not only the negative implications on the environment but also reduces costs. This paper provides an experimental dataset of utilizing biodegradable waste materials as environmentally friendly drilling fluid additives. The data were collected through experimental evaluations of several waste materials including Potato Peels Powder (PPP), Mandarin Peels Powder (MPP), Fibrous Food Waste Material (FFWM), Palm Tree Leaves Powder (PTLP), Grass Powder (GP), and Green Olive Pits\u27 Powder (GOPP). The data presented herein are the raw results of the experiments, which were conducted to examine the ability of the biodegradable waste materials to improve the water-based drilling fluids. The data include the effects of adding these waste materials on different drilling fluid properties such as mud weight, filtration, pH, and the rheology. The mud weight was measured using mud balance, the filtration data were collected using API filter press for both low/high pressure and temperature, the pH was measured using pH meter, and the rheology was characterized using viscometer. The dataset is potentially useful to assist researchers working on developing environmentally friendly drilling fluid additives

Experimental Investigation of Environmentally Friendly Drilling Fluid Additives (Mandarin Peels Powder) to Substitute the Conventional Chemicals Used in Water-Based Drilling Fluid

The non-biodegradable additives used in controlling drilling fluid properties cause harm to the environment and personal safety. Thus, there is a need for alternative drilling fluid additives to reduce the amount of non-biodegradable waste disposed to the environment. This work investigates the potential of using mandarin peels powder (MPP), a food waste product, as a new environmentally friendly drilling fluid additive. A complete set of tests were conducted to recognize the impact of MPP on the drilling fluid properties. The results of MPP were compared to low viscosity polyanionic cellulose (PAC-LV), commonly used chemical additive for the drilling fluid. The results showed that MPP reduced the alkalinity by 20-32% and modified the rheological properties (plastic viscosity, yield point, and gel strength) of the drilling fluid. The fluid loss decreased by 44-68% at concentrations of MPP as less as 1-4%, and filter cake was enhanced as well when comparing to the reference mud. In addition, MPP had a negligible to minor impact on mud weight, and this effect was resulted due to foaming issues. Other properties such as salinity, calcium content, and resistivity were negligibly affected by MPP. This makes MPP an effective material to be used as pH reducer, a viscosity modifier, and an excellent fluid loss agent. This work also provides a practical guide for minimizing the cost of the drilling fluid through economic, environmental, and safety considerations, by comparing MPP with PAC-LV

Utilizing Food Waste Product (Date Tree Seeds) to Enhance the Filtration Characteristics in Water-Based Drilling Fluid System: A Comparative Study

Practically, to regulate filtration characteristics of drilling fluid, non-biodegradable materials used commonly have a high cost with side effects on personnel safety and the environment. Hence, eco-friendly additives are needed as an alternative to replace or at least support the commonly used filtration control agents. This experimental investigation examines the possibility of using date tree seeds’ powder (DTSP), as a new eco-friendly fluid loss agent. Under surface and sub-surface conditions (fresh and aged conditions), experiments were executed utilizing low-temperature and low-pressure (LTLP) and high-temperature and high-pressure (HTHP) American Petroleum Institute (API) filter press to comprehend the influence of DTSP on the seepage loss characteristics. The findings were compared with a commonly utilized chemical additive to regulate filtration characteristics of drilling fluid (low viscosity sodium carboxymethyl cellulose (CMC-LV)). Two concentrations of DTSP and CMC-LV were added separately to a reference fluid (RF) to understand the effect of concentration variations on filtration properties. The findings revealed that both DTSP and CMC-LV significantly improved the filtrate and the filter cake when comparing them with the RF under fresh and aged conditions. The findings for fresh conditions also showed that LTLP filtration measurements for CMC-LV additives had almost similar performance as DTSP additives, while HTHP filtration measurements exhibited that the two concentrations of DTSP additives were marginally better than those of CMC-LV additives. For aged conditions, CMC-LV additives were relatively more efficient than DTSP additives for LTLP filtration control experiments. However, DTSP additives were more efficient in improving the filtration characteristics as compared to CMC-LV additives for HTHP filtration control experiments. These results are in aid of shifting the oil and gas industry from using conventional harmful additives to using unconventional eco-friendly additives. This also helps in transforming unwanted food wastes into valuable commercial products, which can revolutionize the domestic and international industries and create new job opportunities, hence minimizing the total cost of drilling fluid and the wastes disposed to the environment

Insights into the Applications of Waste Materials in the Oil and Gas Industry: State of the Art Review, Availability, Cost Analysis, and Classification

This study investigates different types of waste materials and their applicability in the oil and gas industry as well as analyzing various applications of these waste materials in the petroleum industry. This study also explores the availability of these waste materials by performing a statistical analysis in a good number of countries worldwide. The statistical study was performed starting with a study on which countries generate waste the most overall, followed by examining multiple countries and investigating their top three most available waste. The results showed that the USA is the leading country in terms of municipal solid waste generation of 258 million metric tons, followed by China that generates around 220.4 million metric tons and then India that generates 168.4 million metric tons of municipal solid waste. The regions that generate the most food waste are North America and Oceania, providing the availability of food waste in those regions. Most of the palm tree wastes are available in the Middle East and some parts of the USA, while green waste can be found in the USA, China, and the UK. Sawdust wastes are mostly available in Europe and North America, while hay waste is abundant in the USA. Waste materials were also examined for various petroleum industry applications. Food wastes were found to be effective in drilling and completion fluids. Various food waste products were utilized to alter the drilling fluid properties such as potato peels and mandarin peels. Food wastes were also effective in altering the pH of the drilling fluids. Some plant-based wastes such as date trees were effective treatments used to stop lost circulation. Based on biodegradability and toxicity basis, waste materials were also classified into four main categories, which are eco-friendly, biodegradable, non-biodegradable, and toxic using color category classification. In summary, waste materials have the potential to be used in the petroleum industry, and they might as well be a good alternative for the future. As an example, the drilling fluid average cost approximately one-tenth of the total cost of the drilling operation, which is considered a tangible cost. By using waste materials as drilling fluid additives, the cost of the drilling fluid can be minimized. Further investigation and research should be carried out to get a better understanding of the importance of waste materials, and how they can be exploited for future applications in the oil and gas industry

Data Analysis of Lost Circulation Events in the Hartha Formation, Rumaila Field, Iraq

Lost circulation is a complicated problem to be prevented or combatted during drilling through the Hartha formation. Hence, Mud losses remedies are determined to stop or mitigate losses using remedial methods or to prevent mud losses using proactive measures. Lost circulation events are analyzed in more than 300 wells drilled in the Rumaila field to determine the best ranges for the key drilling parameters, which have the greatest chance of minimizing or prohibiting lost circulation issues. Key drilling parameters (e.g. MW, ECD, Yp, RPM, SPM, ROP) at the time of each event are extracted along with the lost circulation remedies attempted, and the outcome of those remedies. Practical field information from the Rumaila field and range of sources are reviewed and summarized to develop an integrated methodology and flowchart for handling lost circulation events in this formation. This paper will be an extended work along with previous comprehensive statistical study and sensitivity analysis models about the Hartha formation. In addition, economic evaluation is conducted for partial, severe, and complete losses to obtain the best field procedures. Proactive approaches are made prior entering the Hartha formation to prevent or mitigate the occurrence of the lost circulation. A broad statistical work, typical drilling fluid properties, and recommended operational drilling parameters are estimated to use during drilling through this formation. Moreover, corrective actions are determined for each type of the mud losses to provide effective remedies, minimize non-productive time, and reduce cost. The best lost circulation strategy to the Hartha formation is concluded and summarized depending on a comprehensive statistical work, the most important courses of the international oil companies, technical papers, textbooks, and economic analysis evaluation to determine the successful remedies for each type of the losses. In addition, engineered solutions and practical techniques have been developed, which will contribute to give a clear image and a coherent understanding in regard this complicated and costly problem in the Hartha formation. This study will present a typical compilation of information regarding traditional and the latest approaches to the lost circulation control. This work attempts to provide useful guidelines and effective solutions for all situations in terms preventive measures, remedial methods, and analytical economic study. In addition, due to the lack of published studies about the Hartha formation, this work can serve as a substantial resource for drilling through this zone

Application of Artificial Intelligence in the Petroleum Industry: Volume Loss Prediction for Naturally Fractured Formations

Recently, artificial intelligence has gain popularity in the drilling industry since more wells are drilled in hostile environments. One of the most difficult problems have been encountering the drilling operation is the problem of lost circulation. The complexity of the lost circulation problem is due to the interaction between the parameters that are causing this issue. The aim of this work is to create artificial intelligence models to predict lost circulation, equivalent circulation density (ECD), and rate of pentation (ROP) prior to drilling for naturally fractured formations. Lost circulation events from 500 wells were collected and analyzed to comprehend the impact of each drilling parameter on lost circulation. The data were cleaned and outliers were removed. Partial least square (PLS), a supervised machine learning algorithm, was utilized to create three models to estimate mud losses, ECD, and ROP before drilling. The models went through a cross-validation process to validate them. In addition, the models were tested with new data that were not used in the process of creating the models. The results showed that the three models can predict mud losses, ECD, and ROP within a reasonable margin of error. Testing the models with new data of 30 wells drilled showed that the models\u27 predictions closely track the actual values from the real data. Moreover, the new models were compared with previously developed models for naturally fractured formations. The new models showed better predictions for the actual values than the previously developed models, suggesting the ability of the new models to predict mud losses, ECD, and ROP within an acceptable error. In addition, a 10% sensitivity analysis was conducted for all models to quantify and understand the effect of each parameter on every model. Mud weight (MW) had the highest impact on the ECD and mud losses models revealing that in order to minimize mud losses and ECD, the first action should be trying to use as low MW as possible. On the other hand, weight on bit (WOB) showed the highest positive influence on the ROP model and total flow area (TFA) of the nozzles showed the highest negative impact on the ROP model. Thus, the models developed in this study can be used to regulate the drilling parameters to minimize mud losses. The methodology used in this study to develop estimation models for mud losses, ECD, and ROP can be applied to create predictive models in other formations if the required data are available

Therapeutic Efficacy of a Formulation Prepared with <i>Linum usitatissimum</i> L., <i>Plantago ovata</i> Forssk., and Honey on Uncomplicated Pelvic Inflammatory Disease Analyzed with Machine Learning Techniques

A single-blind double-dummy randomized study was conducted in diagnosed patients (n = 66) to compare the efficacy of Linseeds (Linum usitatissimum L.), Psyllium (Plantago ovata Forssk.), and honey in uncomplicated pelvic inflammatory disease (uPID) with standard drugs using experimental and computational analysis. The pessary group received placebo capsules orally twice daily plus a per vaginum cotton pessary of powder from linseeds and psyllium seeds, each weighing 3 gm, with honey (5 mL) at bedtime. The standard group received 100 mg of doxycycline twice daily and 400 mg of metronidazole TID orally plus a placebo cotton pessary per vaginum at bedtime for 14 days. The primary outcomes were clinical features of uPID (vaginal discharge, lower abdominal pain (LAP), low backache (LBA), and pelvic tenderness. The secondary outcomes included leucocytes (WBCs) in vaginal discharge on saline microscopy and the SF-12 health questionnaire. In addition, we also classified both (pessary and standard) groups using machine learning models such as Decision Tree (DT), Random Forest (RF), Logistic Regression (LR), and AdaBoost (AB). The pessary group showed a higher percentage reduction than the standard group in abnormal vaginal discharge (87.05% vs. 77.94%), Visual Analogue Scale (VAS)-LAP (80.57% vs. 77.09%), VAS-LBA (74.19% vs. 68.54%), McCormack pain scale (McPS) score for pelvic tenderness (75.39% vs. 67.81%), WBC count of vaginal discharge (87.09% vs. 83.41%) and improvement in SF-12 HRQoL score (94.25% vs. 86.81%). Additionally, our DT 5-fold model achieved the maximum accuracy (61.80%) in the classification. We propose that the pessary group is cost-effective, safer, and more effective as standard drugs for treating uPID and improving the HRQoL of women. Aucubin, Plantamajoside, Herbacetin, secoisolariciresinol diglucoside, Secoisolariciresinol Monoglucoside, and other various natural bioactive molecules of psyllium and linseeds have beneficial effects as they possess anti-inflammatory, antioxidant, antimicrobial, and immunomodulatory properties. The anticipated research work is be a better alternative treatment for genital infections