Hassaan Ahmed - Academia.edu (original) (raw)

Papers by Hassaan Ahmed

All Days, Nov 22, 2017

The research presents an effective way for the optimization of one of the enhanced oil recovery m... more The research presents an effective way for the optimization of one of the enhanced oil recovery mechanism; surfactant-polymer flooding by the application of two stochastic evolutionary algorithms namely Covariance Matrix Adaptation-Evolutionary Strategy (CMAES) and Invasive Weed Optimization (IWO). The optimized parameters include the well placement, time duration for water and chemical flooding, and chemical injection rates in injection wells while net present value (NPV) served as the objective function.Surfactant Polymer (SP) flooding has proved to be an efficient enhanced oil recovery (EOR) mechanism in recent times. Research has been done on the efficiency of SP flooding by optimizing different properties of surfactant and polymer such that the process results in an improved oil recovery. However, these optimizations are based on the sensitivity studies which limit the researchers to search the optimum solution within a specific domain without extensively exhausted the search space. Stochastic techniques, however, showed a way to efficiently optimizes the SP flooding process even with higher number of optimization parameters.Detailed optimization results for several cases considered in this research are presented. Channeled reservoir and fully heterogeneous reservoir are the two reservoir models used for the optimization of SP flooding process. The maximization of NPV for SP flooding using well placement optimization and without well placement optimization is also compared for both reservoirs utilizing CMAES and IWO. Furthermore, all cases are compared with the base case of simple waterflooding. Statistical analysis is done for all the cases for several realizations and the realizations are ranked according to the best, median and worst, based on the NPV values for each case. The consideration of having such a higher number of optimized parameters is to fully evaluate the potential of considered stochastic optimization techniques to converge to a global maximum for NPV as opposed to conventional sensitivity analysis. Results suggested that these stochastic evolutionary algorithms have a potential to be utilized as the optimization tool for field development of reservoirs having higher number of parameters to be optimized.The successful evaluation of considered stochastic evolutionary algorithms (CMAES and IWO) proved that these algorithms can successfully be used for the optimization of field development plan under higher number of parameters to be optimized that cannot be achieved using sensitivity analysis or gradient based optimization algorithms.

Modeling fluid behavior using conventional nodal analysis software is a common practice in the oi... more Modeling fluid behavior using conventional nodal analysis software is a common practice in the oil and gas industry. However, understanding flow physics helps production engineers to understand the difference between predicted and actual flow behavior. This work presents a methodology applied to a depleting oil and gas field in northern Pakistan. The adopted approach not only helped to overcome vertical lift performance issues in the wellbore, but it also resulted in improved and sustained oil and gas production from the well. Based on these results, wells in the field with vertical lift performance issues were identified and evaluated using the analysis approach presented in this work. Basic petroleum engineering concepts are implemented using a multi-tier approach, and a proposal was outlined to understand the sluggish flow behavior from the well. The analysis approach characterizes the problem as "IPR dominated" or "VLP dominated" flow using the well's historical data and nodal analysis results, identifies the requirement for a new data set, and then operations are planned accordingly. During execution, coil tubing with memory gauges was deployed with a provision to simulate Coil Tubing Gas Lift (CTGL) with single point injection. This arrangement not only resulted in sustained production from the well, but it also provided leverage to gather bottomhole data corresponding to multiple flow parameters during sensitivity analysis. The workflow explains the physics behind oil and gas wells with sluggish liquid production and the inadequacy of conventional nodal analysis software in predicting production rates with certainty. The application of this workflow converted a "sick well" into a "sustained production well," which was previously ruled out for the implementation of ALS techniques during initial screening using conventional nodal analysis software. This novel approach highlighted the "domain of applicability" of conventional nodal analysis software and proposed a detailed workflow for artificial lift candidate selection. This workflow served as the blueprint for the overall evaluation of well productivity in depleting fields with VLP issues.

Day 3 Wed, March 15, 2023, Mar 13, 2023

A high-profile and major contributor exploratory well was at the verge of being a work-over candi... more A high-profile and major contributor exploratory well was at the verge of being a work-over candidate due to badly stuck coil tubing (CT) inside wellbore during routine well intervention operations. The situation got even worst when pin hole was established in CT string inside wellbore. The conventional and primary mechanism to release such CT is to operate hydraulic disconnect, which is an integral part of bottomhole motorhead assembly (MHA), by means of applying desired differential hydraulic pressure however, presence of pin hole restricted the desired differential pressure to communicate at motorhead assembly and to operate it. This work highlighted the importance of "back to the basics" phrase when conventional operating procedures failed to be executed and hence termed as "out of the box solution for coiled tubing retrieval". The method proposed in this work can be used by oil and gas professionals as the last resort to retrieve stuck coil tubing with complications like pin hole and failed hydraulic activation mechanism which will certainly avoid major cost exposure and operations complexities associated with rig assisted work-over. In order to activate the hydraulic disconnect inside motorhead assembly of stuck coil tubing, depth of point of communication was estimated, inside volume of coiled tubing upto point of communication was calculated, additional pressure requirement to operate motorhead assembly was identified and heavy mud was pumped at a very slow rate in order to create hydraulic imbalance across coil tubing. Additional pressure due to hydraulic imbalance across coiled tubing was not sufficient to operate motorhead assembly therefore once the heavy mud reached point of communication; by calculation; high pressure pumping was performed in order to give high pressure pulses to motorhead assembly with a hope to activate and release it. All the theoretical calculations and planning based on above went as per plan and coiled tubing was successfully released. The proposed principle of stuck Coil Tubing retrieval is new to oil industry as no literature has been found related to it. It not only saved a high profile well from expensive work-over operation but also the reputation of the exploration and production and service companies involved. The novel approach presented in this paper is inherited from the concepts of fluid mechanics and has been successfully implemented. This methodology has all the merit to be included in the International Well Control Forum (IWCF) as the well control methodology for the stuck coil tubing with pinhole deeper into the well.

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State-of-the-art advanced ultrasonic measurement through the Leaky-Lamb wave imaging technique (m... more State-of-the-art advanced ultrasonic measurement through the Leaky-Lamb wave imaging technique (more commonly known as the flexural waveform analysis) was introduced nearly two decades ago to expand the envelope beyond which the classical pulse-echo evaluation operated. This technology has proven to be a game-changer in cement evaluation through provision of an integrated analysis which deconvolutes beyond the casing-cement interface and investigates further into the third interface. In this work, we integrate the cutting-edge analysis provided by ultrasonic flexural mode with the classical pulse-echo approach to yield a novel well-integrity evaluation blueprint. Subsequently, it is shown how this workflow is applied to an ultra-high pressure (UHP) exploratory well for integrity evaluation which will aid in future optimization of completion strategies and constitute a continuous improvement cycle for other wells. The subject well faced potential integrity related uncertainties due to fishing and cementing related issues. A three-tier approach was adopted to develop the blueprint, starting off with problem identification with respect to the various operations and incidents that occurred on this well. Next, based on the anticipated problems, associated solutions to evaluate the same were investigated by considering the technologies and standard procedures practiced by the industry. Finally, based on the previous two steps, a multi-physics approach was adopted that makes use of a combination of pulse-echo and flexural ultrasonic analysis, in addition to multiple well integrity workflows. Consequently, combination of flexural attenuation and acoustic impedance allows for a comprehensive evaluation of the medium behind the casing through the Solid-Liquid-Gas map. Simultaneously, it is possible to quantify casing thickness and internal radius variations through pulse-echo amplitude and resonance frequency characterization. Furthermore, the Third-Interface-Echo analysis is conducted to determine annulus geometry descriptions and produce a unique insitu casing centralization measurement. The proposed well integrity blueprint contains various building blocks that are key to evaluation processes and provide a linkage-based approach to delineate potential problems. Accordingly, application of this

The UHP exploratory well subject of this study faced with myriad challenges, including fishing, s... more The UHP exploratory well subject of this study faced with myriad challenges, including fishing, sidetracking, and other undesirable incidents with consequences to the 9-7/8" production casing. Torque and drag analysis, preliminary casing wear simulations, and actual drilling parameters pointed towards multiple uncertainties concerning barrier integrity. Consequently, a multi-physics evaluation was conducted including well-integrity logs in a combination of thickness-mode with flexural-mode of the casing. Signals from these independent measurements are then processed to provide robust interpretation of solid-liquidgas behind casing using acquired flexural attenuation and acoustic impedance data. In addition, casing wear is quantified by thickness changes measured through the resonance frequency of the waveform and represented in the form of a joint-by-joint corrosion summary, reporting the average metal loss. Furthermore, propagation of flexural wave-fronts as it leaks to the third interface is tracked to produce a unique image of the annulus geometry in terms of casing eccentricity and acoustic velocity of the medium. Subsequently, the former, provides a quantifiable, unique in-situ casing standoff measurement to be used for centralization evaluation. Application of the developed data-integrated workflow allowed for comprehensively analyzing well integrity barrier condition. Cement barriers were assessed with confidence by flexural imaging, which were difficult to determine solely with pulse-echo. Additionally, annulus imaging using third interface-echo (TIE) helped in characterizing the potential causes of casing wear and quality of cement behind casing by providing actual in-situ casing standoff. It was observed that casing wear was at the low side of the wellbore where the casing had the least standoff as shown by flexural waveform TIE arrivals. Moreover, high percentage of metal loss was correlated to regions with centralization lower than 40-50%. Integration of these results with casing side forces and remaining casing strength (under worst case scenario) was performed to evaluate casing endurance for future drilling, production, and injection operations.

HPHT well environments present design & operational challenges that could potentially translate i... more HPHT well environments present design & operational challenges that could potentially translate into well failure with high consequences. Several risk elements can combine into a complex hazard causing serious threat to well design & integrity. Risk elements could be complex downhole environment, material deration, material incompatibility with the completion/packer fluids and other treatment fluids, metallurgy imbalances etc. This case study presents early life production tubing integrity failure highlighting gaps and suggestions to adopt an integrated risk mitigation approach.

The case study presents an integrated workflow with the focus on the thermal analysis of the comp... more The case study presents an integrated workflow with the focus on the thermal analysis of the completion string, wellhead and surface network. The research outcome are the temperature profiles under various production scenarios that are used as the justification of the installation of wellhead cooler on an exploratory well of lower Indus basin in Pakistan. The advent of deep well drilling in high temperature and high pressure formations posed serious concerns for drilling, completion and facility design engineers as these are one of the key parameters for material and fluid selection for completion string. The uncertainty in these parameters throughout the operational life of the well may cause an over-designed or underdesigned well completion and production facility. The equation gets further complex if the inherent uncertainty in type and quantity of produced fluids is neglected or underestimated. To overcome these challenges, a workflow considering the downhole completion considerations and wellhead treatment of produced fluid; in consideration of wellhead temperature; is proposed. This paper presents reservoir and completion design considerations of an exploratory well in lower indus basin. Effect of various production scenarios on temperature profile are considered based on the possible drive mechanisms of hydrocarbon production. The analysis includes the development of completion string model for well S-X1 and coupling the same with the hydrocarbon processing facility through surface network. The model is calibrated using history matching of temperature profile using the production data and sensitivity analysis of various parameters was performed. Based on the simulation results, it was observed that the proposed workflow using industry standard commercial software for thermal analysis is a more realistic approach for temperature prediction using production profiles. The proposed workflow will serve as the guidelines for wellhead and surface facility design under various expected production scenarios.

This paper was selected for presentation by an SPE program committee following review of informat... more This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the autho r(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, di stribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyrig ht.

Exposure of production annulus with formation fluids due to tubing-casing communication is unfavo... more Exposure of production annulus with formation fluids due to tubing-casing communication is unfavorable scenario throughout well's life cycle. The communication paths are always susceptible to aggravate with the passage of time, eventually resulting in complete loss of well integrity due to failure of one of the integral well barriers and potentially causing major risk and hazards to environment and personnel. Accurate and most efficient actions are therefore required on war-foot basis to restore lost integrity. DST of an exploratory well in South Pakistan revealed the corrosiveness of reservoir fluid (26 % CO2), therefore, completed with chrome material. Well remained shut-in due to plant capacity constraints. Soon after well commissioning, pressurized annulus was reported. Initial investigation depicted hydrocarbons in annulus, however, Distributed Temperature Sensing (DTS) was later used to accurately locate the leak path. Conventional remedial options including tubing patch and work-over were ruled out due to extreme reservoir parameters and associated high cost as well as production curtailment. Placement of Resin-Based Isolation Plug (RBIP) in annulus was found to be the most feasible option to restore well integrity. Coiled tubing conveyed DTS was carried out in shut-in and flowing conditions that confirmed depth of leak path in completion string. Main reason of implementing this diagnostic technique was the unavailability of conventional logging tools compatible with high temperatures. DTS was run in conjunction with correlating tool (CCL) for precise depth determination with respect to completion jewelry. After exploring pros and cons of conventional remedial techniques, treatment through annulus was the only remedial option left to block the leakage path in completion string therefore, placement of RBIP on top of leak point was planned. This plug, once solidifies, restricts tubing movement due to thermal effects when exposed to production loads. Therefore, extensive stress analysis was essential to evaluate the integrity of anchored completion due to plug under various production loads throughout the well's lifecycle. With all possible risks critically assessed, RBIP along with bridging spacers was successfully poured in annulus during rig less operation. Well was kept in flowing conditions towards plant to avoid production curtailment throughout the operations. Currently, well is flowing, maintaining the necessary feed at plant and fulfilling country's gas demands with well integrity intact. 2 SPE-201174-MS Tubing-Casing communication and pressurized annulus has become common problem and plays significant role in maintaining the reputation and progress of E&P companies. Conventional methods are readily available to rectify such problems however, there are scenarios where wellbore conditions / parameters and economic feasibility may restrain their implementation. RBIP is a new technique in restoring well integrity through annulus and is successfully implemented for the first time not only in Pakistan Petroleum Limited (PPL) but in Pakistan.

In recent times, volatility has been observed in oil and gas prices which has resulted in lower r... more In recent times, volatility has been observed in oil and gas prices which has resulted in lower rig count and fewer wells being drilled. Consequently, engineers working in unconventional plays have lower margin of error while planning new wells and are under increasing pressure to minimize the projects costs. One important aspect of projects in tight plays is the well completion design and stimulation strategy. Hydraulic fracturing is typically used to create high permeability channels to have better reservoir coverage. Hydraulically induced fractures drive the well economics as drainage radius around wellbore is limited to their extension in low permeability matrix. Thus, reservoir and production engineers need to use the right tools and appropriate methodologies to predict hydraulic fracture half lengths. However, despite spending 20-50% of well cost on compatible completion and stimulation operations, hydraulic fracturing is a

SPE-214174-MS Control Forum (IWCF) as the well control methodology for the stuck coil tubing with... more SPE-214174-MS Control Forum (IWCF) as the well control methodology for the stuck coil tubing with pinhole deeper into the well.

In order to activate the hydraulic disconnect inside motorhead assembly of stuck coil tubing, depth of point of communication was estimated, inside volume of coiled tubing upto point of communication was calculated, additional pressure requirement to operate motorhead assembly was identified and heavy mud was pumped at a very slow rate in order to create hydraulic imbalance across coil tubing. Additional pressure due to hydraulic imbalance across coiled tubing was not sufficient to operate motorhead assembly therefore once the heavy mud reached point of communication; by calculation; high pressure pumping was performed in order to give high pressure pulses to motorhead assembly with a hope to activate and release it. All the theoretical calculations and planning based on above went as per plan and coiled tubing was successfully released.

The proposed principle of stuck Coil Tubing retrieval is new to oil industry as no literature has been found related to it. It not only saved a high profile well from expensive work-over operation but also the reputation of the exploration and production and service companies involved.

The novel approach presented in this paper is inherited from the concepts of fluid mechanics and has been successfully implemented. This methodology has all the merit to be included in the International Well Control Forum (IWCF) as the well control methodology for the stuck coil tubing with pinhole deeper into the well.

Day 3 Wed, March 24, 2021

Casing degradation evaluation is of prime importance to ensure well integrity system reliability ... more Casing degradation evaluation is of prime importance to ensure well integrity system reliability and sustainability. Multi-finger calipers have been around for more than 50 years and are used to assess internal casing damage. In addition, high resolution ultrasonic imaging, introduced relatively recently, determines casing thickness by transmitting pulse-echo waveforms to initiate thickness-mode of the casing through induction of mechanical resonance. A high-profile exploratory gas well was at stake of being compromised due to fishing and cable sticking incidents in the 7-inch section. In this work, a novel combination of multi-finger caliper and ultrasonic imaging is investigated to accurately determine metal loss with assistance of hybrid threedimensional casing morphological visualizations which is then utilized to validate casing derating models and ensure well integrity. In order to evaluate the casing condition, it was decided to run a 24-finger caliper tool and to make up for...

Al-Yousef for their generous help and support for this project. I would also like to express my g... more Al-Yousef for their generous help and support for this project. I would also like to express my gratitude to all the faculty members of the Petroleum Engineering Department at KFUPM. To all of them, I appreciate what they have done to help me in my scholastic and professional growth. I would like to acknowledge the Centre of Petroleum & Minerals (CPM) at Research Institute (RI) in KFUPM and Saudi Aramco for arranging financial support of this research project

Background: Following the harvest of Eucalyptus grandis Hill ex Maiden, Eucalyptus globulus Labil... more Background: Following the harvest of Eucalyptus grandis Hill ex Maiden, Eucalyptus globulus Labill, Eucalyptus dunnii Maiden and Pinus taeda L. forests, an important proportion of the aerial biomass is left to decompose on the site. The decomposition process is known to alter the dynamics of nutrients in the soil, particularly N, which is essential for the growth of the next turn of the plantation. The decomposition of E. grandis, E. globulus, E. dunnii and P. taeda harvest residues (leaves/needles, twigs and bark) was studied, following individual incubation of each residue type for 6 months under controlled temperature and humidity. Net N mineralization was also determined. Chemical characteristics of the residues were tested to identify those that affect the rate of decomposition and N release. Results: The highest decomposition rates were found for Eucalyptus leaves and P. taeda needles, but the proportion of C respired by P. taeda needles was lower than that of Eucalyptus leaves. No differences among species were found in the amount of CO 2 produced during incubation of twigs. The lowest decomposition rates corresponded to Eucalyptus bark. Although C loss was related to many residue characteristics, the closest relationship was observed with their C:N ratio. Higher amounts of mineral N were produced by decomposition of E. grandis and E. dunnii leaves than P. taeda needles and E. globulus leaves. Bark decomposition produced N immobilization, irrespective of the species, and for twigs, this was also true, except for P. taeda. The net N mineralization by decomposition of Eucalyptus residues was highly correlated with their total N content and the C:N and lignin:N ratios. Conclusion: The total N content and the C:N ratio of residues can be used to satisfactorily assess the decomposition and net N mineralization potential of different residues types, avoiding the How to cite this paper:

Day 2 Tue, March 09, 2021, 2021