Oil Recovery Performance And Asphaltene Deposition Evaluation Of Miscible And Immiscible Carbon Dioxide Or Nitrogen Huff-n-Puff Processes In Shale Reservoirs

The utilization of gas enhanced oil recovery to extract oil from unconventional reservoirs has become a widely discussed topic, as it has proven to be effective in significantly boosting oil recovery rates. Among various enhanced oil recovery methods, Gas Enhanced Oil Recovery (GEOR) is a frequently implemented approach. However, a significant challenge encountered during the process of injecting Carbon Dioxide (CO2) or Nitrogen (N2) to displace oil is the occurrence of asphaltene precipitation and deposition, which can impede production. This work is an experimental study to examine the effects of cyclic (huff-n-puff) CO2 or N2 processes on oil recovery performance and asphaltene deposition using Eagle Ford shale cores. The minimum miscibility pressure (MMP) was first determined for CO2 and N2, and then different injection pressures (miscible and immiscible) were chosen to carry out CO2 and N2 huff-n-puff tests. Miscible and immiscible pressures were selected to implement the huff-n-puff test for CO2 and N2. Pore size distribution was analyzed to highlight the impact of asphaltene particles on pore plugging

Enhanced Oil Recovery from Shallow Depths Through the Use of Tight Radius Lateral Drilling [abstract]

Only abstract of poster available.Track I: Power GenerationThere are many heavy oil fields in the world where the oil does not easily flow to the well and conventional production is thereby limited, or currently not economically viable. Missouri alone has billions of barrels of oil along its western edge, that lie just too deep for conventional surface mining (similar to that of the tar sands of Alberta) and yet have an oil that is too heavy to be easily recovered by normal oil well production. Where this oil can be extracted it will add significantly to the reserves of the country. Missouri S&T pioneered the use of high-pressure waterjets as a means of drilling long horizontal holes underground - a technology validated in field tests with Sandia National Laboratories. The technique allows the turning of a drill from an existing vertical well in a radius of less than 9 inches, whereas conventional tools require 20 ft. Once the turn has been made, the drill can then penetrate out horizontally. Once the horizontal wells have been established then one of two different approaches can be taken. The wells may be hydrofraced, as is conventionally done, for example in shale gas recovery, or the sand might be mined. Once the well has been drilled to the edge of a defined area, the drilling head can be reconfigured into a reaming mode in which the jets cut into and mine the oil bearing rock (which in Missouri is up to 30 ft thick). By disintegrating the rock and pumping it to the surface, (in the same way as in Alberta) using a hot water solution, the oil can be removed from the sand, which can then be mixed with a small amount of a binder and re-pumped back into the reamed cavity to provide support for adjacent mining of the material so that all the rock can be mined, and all the oil is recovered. In this way the oil can be recovered without the environmental impacts of the open pit tar sand operations

Application of Artificial Neural Networks in the Drilling Processes: Can Equivalent Circulation Density Be Estimated Prior to Drilling?

As the drilling environment became more challenging nowadays, managing equivalent circulating density (ECD) is a key factor to minimize non-productive time (NPT) due to many drilling obstacles such as stuck pipe, formation fracturing, and lost circulation. The goal of this work was to predict ECD prior to drilling by using artificial neural network (ANN). Once ECD is recognized, the crucial drilling variables impact ECD can be modified to control ECD within the acceptable ranges. Data from over 2000 wells collected worldwide were used in this study to create an ANN to predict ECD prior to drilling. Into training, validation, and testing sets, the data were splitted. 70% of the data utilized for training, the other part used for validation and testing to avoid overfitting and create a generalized network that can perform well on new data. Based on the mean square of error (MSE), a decision was made to have one hidden layer with twelve neurons, this scenario was selected since it gave the lowest MSE among other scenarios. Multiple training functions were tested to train the network, Bayesian regularization (BR) algorithm was chosen from the other algorithms since it had the lowest MSE and the highest R-squared. After optimizing the weights and biases, the results revealed that the created network has the ability to estimate ECD with an overall R-squared of 0.982, which is very high. This result gives an indication that the created network can predict ECD prior to drilling globally within a very small margin of error. Due to the availability of large historical data sets in the petroleum industry, the ANN can be used to make better future decisions to minimize NPT and the cost of drilling

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

Regularized Ridge Regression Models to Estimate Static Elastic Moduli from Wireline Measurements: Case Study from Southern Iraq

Elastic moduli such as Young\u27s modulus (E), Poisson\u27s ratio (v), and bulk modulus (K) are vital to creating geomechanical models for wellbore stability, hydraulic fracturing, sand production, etc. Due to the difficulty of obtaining core samples and performing rock testing, alternatively, wireline measurements can be used to estimate dynamic moduli. However, dynamic moduli are significantly different from elastic moduli due to many factors. In this paper, correlations for three zones (Nahr Umr shale, Zubair shale, and Zubair sandstone) located in southern Iraq were created to estimate static E, K, and ν from dynamic data. Core plugs from the aforementioned three zones alongside wireline measurements for the same sections were acquired. Single-stage triaxial (SST) tests with CT scans were executed for the core plugs. The data were separated into two parts; training (70%), and testing (30%) to ensure the models can be generalized to new data. Regularized ridge regression models were created to estimate static E, K, and ν from dynamic data (wireline measurements). The shrinkage parameter (α) was selected for each model based on an iterative process, where the goal is to ensure having the smallest error. The results showed that all models had testing R2 ranging between 0.92 and 0.997 and consistent with the training results. All models of E, K, and ν were linear besides ν for the Zubair sandstone and shale which were second-degree polynomial. Furthermore, root means squared error (RMSE) and mean absolute error (MAE) were utilized to assess the error of the models. Both RMSE and MAE were consistently low in training and testing without a large discrepancy. Thus, with the regularization of ridge regression and consistent low error during the training and testing, it can be concluded that the proposed models can be generalized to new data and no overfitting can be observed. The proposed models for Nahr Umr shale, Zubair shale, and Zubair sandstone can be utilized to estimate E, K, and ν based on readily available dynamic data which can contribute to creating robust geomechanical models for hydraulic fracturing, sand production, wellbore stability, etc

Mud Loss Estimation using Machine Learning Approach

Lost circulation costs are a significant expense in drilling oil and gas wells. Drilling anywhere in the Rumaila field, one the world\u27s largest oilfields, requires penetrating the Dammam formation, which is notorious for lost circulation issues and thus a great source of information on lost circulation events. This paper presents a new, more precise model to predict lost circulation volumes, equivalent circulation density (ECD), and rate of penetration (ROP) in the Dammam formation. A larger data set, more systematic statistical approach, and a machine-learning algorithm have produced statistical models that give a better prediction of the lost circulation volumes, ECD, and ROP than the previous models for events. This paper presents the new model, validates the key elements impacting lost circulation in the Dammam formation, and compares the predicted outcomes to those from the older model. The work previously presented by Al-Hameedi et al. (http://www.onepetro.org, 2017a; http://www.AADE.org, 2017b) provided a platform for predicting the severity of lost circulation incidents in the Dammam formation. Using the new models, the predictions closely track actual field incidents of lost circulation. When new lost circulation events were compared with predictions from the old and new models, the new model presented a much tighter prediction of events. Three equations for optimizing operations were developed from these models focusing on the elements that have the highest degree of impact. The total flow area of the nozzles was determined to be a significant factor in the ROP model indicating that nozzle size should be chosen carefully to achieve optimal ROP. Good modeling of projected lost circulation events can assist in evaluating the effectiveness of new treatments for lost circulation. The Dammam formation is a significant source of lost circulation in a major oilfield and warrants evaluation of the effectiveness of lost circulation treatments. These techniques can be applied to other fields and formations to better understand the economic impact of lost circulation and evaluate the effectiveness of various lost circulation mitigation efforts

Experimental Investigation of Bio-Enhancer Drilling Fluid Additive: Can Palm Tree Leaves Be Utilized as a Supportive Eco-Friendly Additive in Water-Based Drilling Fluid System?

Serious problems will be presented due to using conventional chemical additives to regulate the drilling mud properties, as they have health, safety, and environmental side effects. Thus, there is a considerable necessity for alternative multifunctional bio-enhancer drilling mud additives, which can assist in optimizing the drilling fluid specifications and enhance its effectiveness with the least effects on the environment and the drilling personnel safety. The effects of adding two concentrations of palm tree leaves powder (PTLP) to water-based mud were conducted under fresh and aged conditions using standard API drilling fluids testing methods such as rheometer/viscometer, pH meter and temperature, and filter press. All tests results were minutely recorded to understand the influence of PTLP additives on the drilling mud properties. The results indicated that PTLP as an effective material to be used as pH reducer, viscosity reducer, and as an excellent filtration loss control agent under the surface and sub-surface conditions. Thus, PTLP has excellent feasibility to be utilized as biodegradable drilling mud additive replacing or at least supporting other conventional chemical additives, which have usually been used for the same purposes such as lignosulphonate, chrome-lignite, and Resinex. Finally, this work can serve as a practical guide for minimizing the cost of the drilling fluid and reducing the amount of non-biodegradable waste disposed to the environment

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