Petrophysical properties assessment using wireline logs data at well#3 of Srikail gas field,Bangladesh

This study focused on the quantitative analysis of the petrophysical parameters in characterizing the reservoir properties of the Srikail gas field using multi-scale wireline logs.Petrophysical parameters(shale volume,porosity,water saturation and hydrocarbon saturation)were estimated from the combination of gamma ray log,resistivity log,density log and neutron log for three hydrocarbon(gas)-bearing zones at well#3.At the first time,log records at 0.1 m and 0.2 m intervals were read for this study.Result showed the average shale volume is 21.07%,53.67%and 51.71%for zone-1,zone-2 and zone-3,respectively.For these zones,the estimated average porosity was 35.89%,29.83%and 28.76%,respectively.The average water saturation of 31.54%,16.83%and 23.39%and average hydrocarbon saturation of 68.46%,83.17%and 76.61%were calculated for zone-1,zone-2 and zone-3,respectively.Thus zone-2 is regarded the most productive zone of well#3.It was found that the values of some parameters(porosity,hydrocarbon saturation and permeability)are higher than the existing results.Therefore,this study confirmed that the log reading at minute/close interval provides better quantitive values of the reservoir’s petrophysical properties.It is expected that this result will contribute to the national gas field development program in future.

Determination of the Minimum Testing Time for Wireline Formation Testing with the Finite Element Method

The wireline formation tester （WFT） is an important tool for formation evaluation, such as calculating the formation pressure and permeability, identifying the fluid type, and determining the interface between oil and water. However, in a low porosity and low permeability formation, the supercharge pressure effect exists, since the mudcake has a poor sealing ability. The mudcake cannot isolate the hydrostatic pressure of the formation around the borehole and the mud seeps into the formations, leading to inaccurate formation pressure measurement. At the same time, the tool can be easily stuck in the low porosity/low permeability formation due to the long waiting and testing time. We present a method for determining the minimum testing time for the wireline formation tester. The pressure distribution of the mudcake and the formation were respectively calculated with the finite element method （FEM）. The radius of the influence of mud pressure was also computed, and the minimum testing time in low porosity/low permeability formations was determined within a range of values for different formation permeabilities. The determination of the minimum testing time ensures an accurate formation pressure measurement and minimizes possible accidents due to long waiting and testing time.

Study of Smart Grid Communication Network Architectures and Technologies

Smart Grid (SG) is an emerging paradigm of the modern world to upgrade and enhance the existing conventional electrical power infrastructure from generation to distribution to the consumers in a two-way communication fashion to automate the electrical power demand and supply and make this a cyber-physical system. SG infrastructure key elements, such as smart meters, circuit breakers, transformers, feeders, substations, control centers, grid stations, are required well-formed communication network architectures. SG infrastructure is divided into three main communication networks architectures, such as HAH, NAN, and WAN. Each of these communication network architectures requires reliable, stable, secure, high data rate at real-time with the help of different wireline and wireless communication technologies from HAN to WAN networks. To understand the complete concepts about SG, a concise review is presented and it will help the readers to get foundations of communication network architectures and technologies of SG.

Petrophysical Tutorial, Lessons Learned, and Evaluation Workflow: A Case Study in the Power River Basin

The objective is to empower the reader and scientific community with the knowledge and specific applicable equations to then reproduce the critical rock and fluid attributes in the Powder River Basin. To then continue to unravel the basin and its potential (both conventionally and unconventionally). The overall goal is to ensure the transfer of knowledge and communication of a petrophysical workflow that can then also influence application to other basins worldwide. The Powder River Basin is in southeast Montana and northeast Wyoming and is a prolific oil and gas (hydrocarbon-prone) sedimentary basin related to the greater Rockies chain/series of hydrocarbon-bearing basins (ex. Big Horn, Greater Green River, Denver-Jules). In this study, we briefly set-up the geological background of the Powder River Basin and the importance/ relevance to then tackling subsurface petrophysical evaluation on a regional scale. Approximately, 200 wells were evaluated petrophysically by a combined deterministic and inversion-based workflow representing an effort to share best practices, approaches, and the relative trends to apply in the basin to unravel the stratigraphic hydrocarbon potential in place. An extensive workflow involving basic petrophysical approaches such as raw log applicable cutoffs and volume of clay determination are shared as well as extending knowledge and application into advanced petrophysics through geochemical property derivation and impact of those derived properties as well as bound versus free water and hydrocarbon understanding. Results of the petrophysical analysis highlight the varying properties in conventional and unconventional formations (example Niobrara). The results of how and why the petrophysical approach was calibrated and then applied are the primary efforts accomplished.

Research on Pore Pressure-Depth Characteristics in Normal Pressure Reservoir, Bohai Sea Oilfield

In normal pressure of reservoir, formation pressure and depth can not fully reflect the linear relationship between the formation pressure with depth, the change rule of reservoir measured formation pressure and often reduced pressure, understanding unclear cause fluid properties. By introducing basic principles of hydrostatics. The relationship between pressure coefficient and mathematical depth is discussed by mathematical induction analysis of measured pressure data of nearly 50 normal pressure reservoirs in Bohai Oilfield. The results show that the reservoir pressure data is linearly distributed with depth, and the pressure coefficient is inversely proportional to depth. When the depth becomes shallower, the pressure coefficient increases and approaches the reservoir level. As the depth increases, the pressure coefficient decreases and approaches the hydrostatic pressure coefficient infinitely. The study can more accurately analyze the reservoir pressure changes, which is helpful to study the oil and water distribution, reservoir connectivity and fluid properties of atmospheric pressure reservoirs.

Investigation of trend between porosity and drilling parameters in one of the Iranian undeveloped major gas fields

Porosity is one of the main parameters that should be considered when a gas or an oil field is assessed.Hence,the availability of porosity is crucial in any rock and formation analysis.However,this parameter is not always available and direct measurement is scarce and usually is confined to appraisal phase of a field.Therefore,in this study it is aimed to find a relationship in order to estimate porosity in afterward phases.The data of 5 appraisal wells of an undeveloped gas field has been gathered to perform this purpose.The full set wireline logging data and drilling data were available.The data inherit high level of fluctuation which is normal with respect to real direct measured data.The smoothed curving was utilized and as a result,the fluctuation was diminished considerably and the feasibility of carrying out the investigation was being established,accordingly.To normalize and gather drilling data in a parameter in order to have a better view and investigation,sigmalog method was employed.It was observed that there is a clear exponential relationship between porosity and drilling data and curve fitting was utilized to conduct a numerical relationship.The curve fitting was established with R^(2)=0.83 and a trustworthy fitting resulted.The results demonstrate the possibility of porosity estimation by using drilling data.Furthermore,a numerical relationship is given for a specific field.The porosity estimation can lead to better analysis of newly drilled rocks and formations leading to more efficient field development strategies.