Effect of Matrix Acidizing on The Performance of Selected Niger Delta Reservoirs

The performance of matrix acidized selected wells from the Tertiary sandstone reservoirs in the Niger/Delta was evaluated, Data obtained was used to evaluate flow efficiency and production performance before and after acidizing. The results showed that Matrix acidizing proven to be the best stimulation technique employed in recent years to remove near wellbore damages and invariably increase productivity. The analysis involves the post net oil and percentage increase in oil achieved after acidizing, well inflow performance quality indicator and decline rate analysis

Formulation and Evaluation of Synthetic Drilling Mud for Low Temperature Regions

The temperate world such American and Canada are extensively increasing environmental legislations against oil-based muds and increasing exploratory activities in the offshore, it imperative to develop an oil based drilling muds that have resistance to the weather and relatively stable rheological properties at low temperature of -5oC to 20oC. This study investigates the use of non-edible algae oil to formulate ethyl biodiesel as based fluid for drilling mud that can perform the same function as convectional oil based drilling fluid and as well comply with the HSE (Health, safety and environment) standard in the temperate region and offshore environment. Experimental tests were performed at temperature condition of -5oC to 20oC on the synthetic ethyl biodiesel oil based mud samples so as to evaluate the rheological properties of the drilling mud formulations. The synthetic oil based was obtained from offshore drilling company and was used as control experiment. The following tests were run on these muds including; viscosity pH, gel strength, density and filtration tests at varied temperature and constant pressure and toxicity test to determine their usability in the defined conditions

An Improved Semi-Analytical Approach for Predicting Horizontal and Multilateral Well Performance

Field development and economic evaluation of hydrocarbon demand for an accurate model for predicting horizontal well performance as horizontal and multilateral wells have become far more prominent in the industry than vertical wells. Several approaches for modelling horizontal well performance have been studied and reported in the literature. Analytical approach is the easiest with large inaccuracy in the prediction of the horizontal well performance because of inability to apply it in reservoir-wellbore coupling equation. Numerical approach is more reliable for field application than analytical approach. However, it involves iterative nature that requires longer computational times. Semi-analytical approach is simpler and sufficiently exact for field applications if the governing fundamental flow equation is accurately modelled. This study presents a new semi-analytical model for predicting horizontal and multilateral well performance, which includes friction, acceleration and accumulation induced pressure drop along horizontal well length into the governing fundamental flow equations. The outcomes of the proposed model have been validated by field data gotten from gauge rate of 5660stb/d at steady-state condition. The estimated steady flow rate of 5593.9 stb/day obtained from the new approach shows an error of 1.2% which is seen to be more accurate than steady flow rate values obtained by four previous models that exhibited higher percentage errors when compared to gauge reading

THE IMPACT OF PERFORATION GEOMETRY ON OIL WELL PRODUCTIVITY

The increase in demand for oil and gas today requires oil operators to maximize productivity. In order to produce more fluid from the reservoir into the wellbore, perforations must penetrate considerably beyond invaded zone with impaired permeability. The production engineers must take advantage of the perforation controllable parameters to maximize the well productivity. In this study, a simple analytical model incorporating perforation length, radius, and shot density was used to analyze oil well productivity. The results shows that the production rate can be increased by the perforation length, radius, and shot density. The drawdown pressure was reduced with increase in the perforation length and shot density. Higher fluid velocity was controlled with increase in the shot density, length and radius of perforation. The length of perforation and shot density are better in optimizing well productivity. Optimum perforation parameters are required as further increase result in increase in cost relative to the productivity

The use of bio-diesel based additive as rheology improver and pour point depressant of Nigerian waxy crud

The chemical method has proved to be the most effective mitigating method of wax deposition in petroleum system as it deals with the root cause of wax formation. Most of the commercial chemicals in the industry are very expensive and toxic. This paper aims the use of biodiesel based additives for improving the rheological behavior and pour points of waxy crude from Nigeria field. The biodiesels derived additives gave better performance than the commercial chemical and the seed oils as greatly improvement in rheology and pour point values of the waxy crude were observe

A Realistic Model for Estimating Productivity Index of Vertical Well Using Wellhead Data

Productivity index calculation has been an established tool for formulating inflow performance relationship in petroleum production engineering field. The accuracy in its prediction is highly desirable to petroleum industry to predict the well production efficiency and aid in economic analysis of the well. Inability to accurately model and predict flowing bottom-hole pressure in a well may result in erotic value of productivity index of a well. This paper present an improved model for estimating flowing bottom-hole pressure and analyse its effect on productivity index value of a vertical well without ignoring any pressure resisting terms in the governing thermodynamic equation. Satisfactory pressure differential and productivity index results were obtained at any location in the wellbore, at all time and at both steady and unsteady state period using the newly developed model. Generally the flow phenomenon after shut in requires sufficient time to stabilise or advance to pseudo steady or steady state condition has been demonstrated by this study compared with the existing models that stabilised throughout the flowing period. This study also proves that inaccuracy in the results of existing models were not only caused by the effect of pressure restriction due to friction as opined by Guo et al but may have due to oversight of all pressure restriction term in the fundamental governing equation of flowing fluid in a vertical wellbore

SUITABILITY OF JATROPHA OIL AS SURFACTANT IN STEAM ASSISTED RECOVERY OF NIGERIA BITUMEN.

More ways to improve the normal high rates of steam assisted bitumen recovery techniques such as SAGD (Steam assisted gravity drainage) and CSS (Cyclic steam simulation) have been studied for some years now, and It has been discovered that the addition of surfactants on ore or injecting it with steam has recovered more bitumen than the injection of the typical steam, but due to the cost and reduction in availability of petro surfactants feed stock and the food competition created by using an edible feedstock for biodiesel surfactant there is need for the use of an alternative feedstock for biodiesel surfactants. In this project, the focus is on the use of jatropha oil (a non‐edible feedstock) for biodiesel surfactant production was proposed. The paper features series of experiments that were carried out to compare the strength of extraction of bitumen from tar sands using steam from water and steam or vapor from biodiesel (jatropha biodiesel) water mixture after spraying the core with biodiesel and finally toluene. The core was modified from the tar sand gotten from Imeri village in the southwestern part of Nigeria. The samples treated with biodiesel had better and improved recovery than the one with just steam from water, while toluene gives the over‐all best recovery. Copyright of Petroleum & Coal is the property of Slovnaft VURUP a.s. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract

Modelling Minimum Flow Rate Required for Unloading Liquid in Gas Wells

Liquid loading in gas well has been an interest in the Oil and Gas sector due to the reduction of ultimate recovery and also the reduction of production from such wells. Several authors have presented various models for predicting the beginning of liquid loading in a gas well, yet there are regular errors in the model outcomes. Turner et al. based his critical model on a presumption that liquid droplet is spherical and stays that way throughout the wellbore. Li’s model developed later on based on his postulation that droplets are flat in shape and stays that way throughout the wellbore. In reality, when producing in a gas well, under pressure variation, the liquid droplets alternate between sphere-shape and flat shape. Hence there is a need to incorporate the liquid droplet deformation coefficient in the liquid loading governing equation. The newly presented model considered deformation coefficient to justify irregular changes in liquid droplet due to pressure variation during the simultaneous flow of gas and liquid droplet in gas wells, therefore, predict the critical flowrate correctly as the droplet fluctuates between spherical and flat shape. The results from the newly developed model of the critical flowrate using test data provided by Coleman et al. show that the modified critical flowrate is closer to the test flow rate than the other existing models as the error obtained is -9.12688%

Comparative analysis of the performance of hydrophobically associating polymer, xanthan and guar gum as mobility control agent, in enhanced oil recovery application.

This study aimed at evaluating the performance of hydrophobically associating polymer (HAPAM), xanthan gum, and guar gum in enhanced oil recovery (EOR) processes. Their performances in terms of oil recovery applications were investigated through rheological behavior analysis and core flooding experiments. Rheological studies reveal shear thinning characteristics with HAPAM showing superior rheological behavior at elevated shear rates for all concentrations tested. Core flooding tests were conducted on different sandstone core samples with similar petrophysical properties to evaluate the EOR performance using the three polymers. Cumulative oil recovered after waterflood implies that HAPAM shows better oil recovery capability with 41.1, 62.4, and 63.5% oil recovery compared to xanthan achieving 32.8, 33.7, and 56.2% and guar gum achieving 41.8, 57.1, and 61.2% oil recovery using the three concentrations; concentration 1, 2 and 3 (1,000, 4,000 and 6,000 ppm), respectively. The superior performance by HAPAM was also evident in its lesser amount of permeability damage after flooding with 28.3% concentration

Dataset on the beneficiation of a Nigerian bentoniteclay mineral for drilling mud formulation

This paperpresentsdatasetonthebeneficiation ofaNigerianclay mineral fordrillingmudapplication.Theexperimentaldesign applied usedaResponseSurfaceDesign(RSM),whichinvolved24 (2-Level, 4-Factors)togeneratestatisticalmodels,andanalyzethe dataset. Theindependentvariableswere(Bentonite; X1), (Polymer; X2), (SodiumCarbonate, X3) and(AgingTime; X4). Therheological properties ofinterest,whichformstheresponsevariables,were selected basedontheAPIspecification 13-Afordrillinggrade bentonite.Theoutcomesshowthatthesecond-orderstatistical models derivedfromresponses fitted wellwiththeexperimental results. Predictivemodelsobtainedfromthestatisticalcharacter- ization ofthebeneficiation processwouldallowforthedesignand cost-effectiveplanningoftheprocedure.Thebeneficiation ofthe clay usingsodiumcarbonateandKelzans XCDpolymerensuedin an improvementintherheologicalpropertiesoftheformulated drilling mud.ThesepropertieswerecomparablewiththeAPI specification 13-Afordrilling fluid material