Petrophysical Analysis and Flow Units Characterization for Abu Madi Pay Zones in the Nile Delta Reservoirs

Field development typically requires detailed petrophysical analysis and well defined hydraulic flow units for comprehensive formation evaluation and reservoir characterization. In the present study, pay zones petrophysics are studied using an assembly of well log data from 8 wells together with core plugs measurements. Petrophysical analysis showed a good reservoir quality with average water saturation increasing toward the East and Southeast of the study area. Using a multi-linear regression technique on well logs and core data, permeability is estimated at well locations for flow unit characterization and flow capacity calculation. Results showed that five hydraulic flow units are identified through the studied wells, with relatively good correlation. Such correlation indicated a good continuity in the net pay zone of Abu Madi Formation in the Nile Delta reservoirs. The developed hydraulic flow units (HFUs) are classified according to its hydraulic conductivity into two main categories: the first category comprises the units with low permeability (K 1270 mD). The reservoir flow capacity (RFC) of these units indicated the development of 4 distinct classes (~11, ~30, ~80, and greater than 130 D.ft). The wells within the Northwestern part of the study area showed three HFUs that relatively vary from those located at the Southeast where two HFUs are only developed. In addition, the Southeastern part of the reservoir is characterized by good RFC as indicated by the development of high order HFUs (3, 4, and 5) compared to the Northeastern part with predominated low order HFUs (1, 2, and 3). Such results are crucial for the efficient field development and profound reservoir management of oil and gas fields in the Nile Delta.

Sequence stratigraphic evaluation for the Abu Madi Formation,Abu Madi/El Qar'a/Khilala gas fields,onshore Nile Delta,Egypt

The present study aims to integrate a large set of geological and geophysical data into a comprehensive model describing the depositional features of the Abu Madi/El Qar'a/Khilala gas fields.The model is based on the sequence stratigraphic framework of the Abu Madi Formation defined using cores,well logs,and time-migrated seismic data.Seismic trace attribute sections and relative acoustic impedance sections are also used.A possible depositional pattern for the main Level Ill is established,based on the lithological and petrophysical information derived from the seismic data analysis.The Abu Madi For-mation can be regarded as a depositional sequence recording the progressive drowning of the incised valley.The sequence is bounded at the base by an erosional unconformity,created by a drop in the level of the Late Messinian Sea,and at the top by a drowning unconformity related to the Early Pliocene transgression.The bottom of Level II divides the Abu Madi sequence into two smaller sequences.In both sequences,gas-bearing traps can be found in the Lowstand Systems Tracts,represented by the fluvial Level Ill and fluvial-deltaic Level Il,respectively.

3D static reservoir modelling of Abu Madi paleo-valley in Baltim Field,Offshore Nile Delta Basin,Egypt

The 3D static reservoir modelling provides a good understanding for the hydrocarbon reservoir distri-bution and properties.This study aimed to construct a static model to study the gas-reservoir potentiality of the Messinian Abu Madi Formation in Baltim Field,offshore Nile Delta Basin.This model was constructed based on the interpretation of the thirty-seven 2D seismic sections besides the analysis of well logs data for five drilled wells(Baltim East-2,Baltim East-3,Baltim East-5,Baltim North-1 and Baltim North-2).The seismic interpretation exposed that the Abu Madi incised valley in Baltim Field is oriented NNW-SSE with width ranges from 5 to 8 km and approximately 32 km in length.The reservoir modelling revealed a relatively homogeneous reservoir facies qualities for gas production in two different zones within the Abu Madi sandstones.The trapping mechanism for these intervals is represented by pinching out in the two sides of the Abu Madi paleo-valley and bounded by two faults in the northern and southern parts of the study area.

Geophysical appraisal of the Abu Madi gas reservoir,Nile Delta Basin,Egypt:Implications for the tectonic effect on the lateral distribution of petrophysical parameters

The tectonic deformation has a significant influence on the hydrocarbon reservoirs properties.The effect of this process focuses on the lateral distribution of the petrophysical parameters characterizing the hydrocarbon reservoirs.The main objective of the current study is to perform a petrophysical examination of the Abu Madi gas reservoir which is the greatest gas-bearing reservoir at Nile Delta Basin in order to examine how far the Messinian tectonics affected the lateral variations of these petrophysical parameters.This petrophysical evaluation was performed based on the wireline log data acquired for five wells,namely,Abu Madi-2,Abu Madi-7,El Qara-3,Nidoco-7,and Nidoco-9 drilled within the Abu Madi Paleo-Valley.The petrophysical assessment for the most promising zone intervals within the Abu Madi sandstones in the inspected wells show that the total porosity varies between 17%and 22%,the effective porosity ranges from 7%to 19%,the shale volume fluctuates between 16%and 30%,hydrocarbon satu-ration varies from 37%to 76%,and the bulk volume of water varies between 0.02 and 0.09.These significant variations in the petrophysical properties of the Abu Madi reservoir are attributed to the tectonic influence during the deposition of the Abu Madi Formation as a part of the Late Miocene synrift megasequence in the Nile Delta Basin.This conclusion confirms that the petrophysical properties of sandstone reservoirs are function of tectonic and structural deformation.

Applications of Amplitude versus Offset and Seismic Attributes for Perceiving Messinian Reservoirs in Nidoco Field, Nile Delta, Egypt

Nile Delta which covers approximately 60,000 square kilometers represents the most important gas province in Egypt whereas its fields provide two-thirds of the gas production in Egypt. The Nile Delta province begins to display its hydrocarbon potentiality in the early 1960s. Nidoco field is located in the shallow water offshore Nile delta. Abu Madi formation (Messinian age) is the most important formation through all the section where it represents the main gas producing reservoirs in the Field. The production of the field is coming from two sand reservoir levels;Abu Madi level 2&3 which are characterized by fluvial-deltaic sandstones. The purpose of this paper is to perceive the Messinian gas bearing reservoirs and channelized sand distribution inside Abu Madi formation using seismic attributes and amplitude versus offset (AVO) technique. The results indicated that the seismic attributes and AVO aided to give a complete picture about the Messinian reservoirs distribution and characterization in the field. Also the results show that there are still promising locations of prospective Abu Madi Level 2&3 which are proposed to be drilled in the field.

Depositional and petrophysical controls on the volumes of hydrocarbons trapped in the Messinian reservoirs, onshore Nile Delta, Egypt

The Messinian sequence in the Nile Delta hosts the most prolific hydrocarbon reservoirs,and is therefore of great importance from the aspect of nonrenewable fuel sources exploration and development strategies.This study presents an investigation for the differential impacts of the depositional and petrophysical attributes on the hydrocarbon volumes trapped in the Messinian reservoirs.Analyses of the pressure data and pressure gradients revealed hydraulically-connected and homogeneous Messinian reservoir rocks.The amounts of Stock Tank Oil and Gas Initially In Places(STOIPP&GIIP)are typically controlled by the depositional primary attributes(matrix content and grain size)which induce several reservoir heterogeneities.The Lower Messinian Qawasim reservoir is subdivided into two main zones:the distal deltaic(zone 1)prograded into proximal deltaic facies(zone 2).The petrophysical reservoir quality in terms of porosity,permeability and water saturation increases upward from zone 1 to zone 2.These are largely controlled by the depositional attributes,and therefore zone 2 with a minimum matrix content,coarse-grained sandstones and mega pore spaces(>150 mm)hosts almost 90%of the STOIIP and 100%of the GIIP.Notably,approximately 78%and 65%of the total STOIIP and GIIP,respectively are confined within the coarse-grained delta-plain distributary channels of zone 2.Similarly,the fluvial sediments(zone 1)of the Upper Messinian Abu Madi Formation host 78%of the GIIP in West Al-Khilala Field and the other 22%is trapped in the overlying zone 2 and is mostly distributed within the sandprone tidal channel and tidal sand bars facies.The channel width/thickness(W/T)ratio largely controls the STOIIP and GIIP values.STOIIP and GIIP display a progressive linear increase with increasing the channel width.This is likely due to increasing the percentage of the good reservoir quality facies within the geologic model as well as increasing the reservoir connectivity with increasing the channel width.