THE SOUTHERN BONAPARTE GULF BASIN - NEW PLAYS

1990 ◽  
Vol 30 (1) ◽  
pp. 52
Author(s):  
J.M. Durrant ◽  
R.E. France
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Well Control ◽  
Lost Circulation ◽  
Marine Source ◽  
Porosity And Permeability ◽  
Basin Floor ◽  
Relationship Of ◽  
New Phase ◽  
Live Oil

Integration of regional exploration data with a new basin model involving progressive basinward salt withdrawal has generated new exploration plays in WA-128-P and WA-211-P, which forms part of the offshore Southern Bonaparte Gulf. This area provides a hydrocarbon habitat that is unique to this part of the Bonaparte Gulf Basin.Three major Palaeozoic megasequences, MS-I, MS-II (A & B) and MS-III, are identified on seismic data and correspond to major stages in the structural and depositional development of the basin, from Silurian through to Triassic times.Early exploration, targeted on structural highs, encountered numerous hydrocarbon shows. Of most recent significance are the Turtle-1 and Turtle-2 wells. Turtle-1 (1984) targeted a midbasin, MS-I high and recovered oil in MS-III. Turtle-2 (1989) tested an additional 510 m-thick, MSII onlap sequence and encountered, within fractured intervals, significant oil and gas influx accompanied by massive lost circulation. Significant live oil was produced on test despite huge damage inflicted to the fracture porosity and permeability during the fourteen-day well control period.Recent geochemical work indicates that the oils recovered from MS-II and MS-III have a common marine source. Oils from MS-III are associated with incompetent seals and meteoric waters and are variably degraded and exhibit low GOR. In contrast, oils of MS-II, associated with competent seals, exhibit high GOR. In consequence, a diversity of new exploratory plays are indicated:Fractured reservoirs in MS-II, stratigraphic onlaps flanking MS-I structures.Stacked turbidites and basin floor fans deposited in the MS-II salt-withdrawal sub-basins.Carbonate banks within the MS-II sub-basin's marginal carbonate complexes.MS-I carbonate structures localised over early salt structures and onlapped by MS-II sediments.Structural and stratigraphic traps of MS-II and III associated with diapiric salt.By virtue of the stratigraphic and structural relationship of MS-II sediments which onlap the flanks of structural highs, these plays have not been previously drilled in optimal locations. Consequently, a new phase of exploration specifically targeted at these plays is now planned to proceed in parallel with exploration of MS-III targets in structural traps. The application of the basin model concepts to these MS-III plays has revealed subtle crestal faulting associated with structural highs. The structural and stratigraphic implications of these observations indicate new plays on the flanks of previously drilled structures.

THE HYDROCARBON POTENTIAL OF THE PENOLA TROUGH, OTWAY BASIN

1995 ◽  
Vol 35 (1) ◽  
pp. 358 ◽  
Author(s):  
R. Lovibond ◽  
R.J. Suttill ◽  
J.E. Skinner ◽  
A.N. Aburas
Keyword(s):  
Early Cretaceous ◽  
Seismic Data ◽  
Oil And Gas ◽  
Direct Detection ◽  
Source Rocks ◽  
Well Control ◽  
Potential Reservoir ◽  
Half Graben ◽  
History Of

The Penola Trough is an elongate, Late Jurassic to Early Cretaceous, NW-SE trending half graben filled mainly with synrift sediments of the Crayfish Group. Katnook-1 discovered gas in the basal Eumeralla Formation, but all commercial discoveries have been within the Crayfish Group, particularly the Pretty Hill Formation. Recent improvements in seismic data quality, in conjunction with additional well control, have greatly improved the understanding of the stratigraphy, structure and hydrocarbon prospectivity of the trough. Strati-graphic units within the Pretty Hill Formation are now mappable seismically. The maturity of potential source rocks within these deeper units has been modelled, and the distribution and quality of potential reservoir sands at several levels within the Crayfish Group have been studied using both well and seismic data. Evaluation of the structural history of the trough, the risk of a late carbon dioxide charge to traps, the direct detection of gas using seismic AVO analysis, and the petrophysical ambiguities recorded in wells has resulted in new insights. An important new play has been recognised on the northern flank of the Penola Trough: a gas and oil charge from mature source rocks directly overlying basement into a quartzose sand sequence referred to informally as the Sawpit Sandstone. This play was successfully tested in early 1994 by Wynn-1 which flowed both oil and gas during testing from the Sawpit Sandstone. In mid 1994, Haselgrove-1 discovered commercial quantities of gas in a tilted Pretty Hill Formation fault block adjacent to the Katnook Field. These recent discoveries enhance the prospectivity of the Penola Trough and of the Early Cretaceous sequence in the wider Otway Basin where these sediments are within reach of the drill.

Could a structurally controlled, hydrothermal dolomite play be operative in Cambro-Ordovician carbonates of the southern Georgina Basin, Queensland?

2016 ◽  
Vol 56 (2) ◽  
pp. 535
Author(s):  
Robbert J. Willink ◽  
Mike J. Bucknill ◽  
Nathan C. Palmer
Keyword(s):  
Fluid Flow ◽  
Seismic Data ◽  
Hydrothermal Fluid ◽  
Oil And Gas ◽  
Fault Zones ◽  
Tight Carbonate ◽  
Porosity And Permeability ◽  
Platform Carbonates ◽  
Hydrothermal Dolomite ◽  
Porosity Development

Hydrothermal dolomitisation of carbonates can create zones of favourable porosity and permeability in otherwise tight carbonate successions. In North America, a number of fields produce oil and gas from such reservoirs that developed along and adjacent to pre-existing fault zones acting as loci for hydrothermal fluid flow. Seismic data across these North American fields are characterised by linear zones of disturbance evident along fault zones where porosity development has occurred. Similar zones of disturbance have been observed on newly acquired seismic over the Toko Syncline in Queensland. Here, these zones extend through a thick Cambro-Ordovician carbonate succession that includes platform carbonates of the Thorntonia Limestone, overlying deeper water deposits of the Arthur Creek Formation that are organic rich and hydrocarbon generative at their base, and also in younger shallow water carbonates of the Arrinthrunga, Ninmaroo, Kelly Creek and Coolibah formations. If these zones of disturbance on seismic also reflect the development of hydrothermal dolomite reservoirs, they provide a new exploration target in the southern Georgina Basin.

The Application of Seismic Data Processing Technology in Kongdian Area

2013 ◽  
Vol 663 ◽  
pp. 876-881
Author(s):  
Qiang Lan ◽  
Qian Zhang
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Low Frequency ◽  
Processing Technology ◽  
Bohai Bay ◽  
Well Control ◽  
Oil And Gas Exploration ◽  
Time Migration ◽  
Energy Compensation ◽  
Static Corrections

Kongdian is located in the eastern part of Bohai Bay. This region has good prospects for oil and gas exploration, but the seismic geologic condition is very complex. After several stages of exploration, a number of significant exploration results have been achieved, but the gradually exposed problems restricted the exploration to go further. In a new round of exploration, the high and low frequency energy compensation technology, advantaged band deconvolution processing technology, dividing frequency high-precision residual static corrections, high-resolution well control-target wavelet deconvolution technology, common scattering point imaging technology and prestack time migration processing technology have been used to improve exploration accuracy. Five potential areas were found in this region according to the new processed seismic data and subsequent interpretation work, achieving the pleasant situation of initial success following the exploration in that year.

scholarly journals PREDIKSI POROSITAS MENGGUNAKAN METODE NEURAL NETWORK PADA LAPANGAN OZZA, CEKUNGAN SUMATRA TENGAH

2020 ◽  
Vol 6 (1) ◽  
pp. 77-86
Author(s):  
Ozza Dinata ◽  
Bagus Sapto Mulyanto ◽  
Resha Ramadian ◽  
Dhimas Arief R
Keyword(s):  
Neural Network ◽  
Seismic Data ◽  
Oil And Gas ◽  
Seismic Analysis ◽  
Analysis Method ◽  
Oil And Gas Exploration ◽  
Linear Approach ◽  
The Neural Network ◽  
Seismic Volumes ◽  
Relationship Of

Information from geological structures that are considered to contain hydrocarbons may not necessarily contain economical hydrocarbons, so additional analysis is needed to determine the position of new wells. Seismic and log methods can be used to determine areas considered prospective for oil and gas exploration. Seismic analysis method developed to be able to integrate seismic data and log data is a neural network. Neural network is a data processing to get a non-linear approach of the statistical relationship of the input data to the output data, then distributed to all seismic volumes. The results of the study of sand reservoir characteristics in the Ozza Field have a porosity value of more than or equal to 20%, and for shale it has a porosity value of less than 20%. The correlation between the original porosity value and predictive porosity is that the higher the porosity value in the original log the higher the value of the neural network porosity, and vice versa. The porosity distribution map in the prospect area has a higher porosity value than the surrounding area. The prospect zone for new exploration is in the southwest area of the study area.

Failure Analysis of the Tripping Operation and its Impact on Well Control

2015 ◽  
Author(s):  
Majeed Abimbola ◽  
Faisal Khan ◽  
Vikram Garaniya ◽  
Stephen Butt
Keyword(s):  
Human Error ◽  
Integrated Control ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Well Control ◽  
Lost Circulation ◽  
Critical Elements ◽  
Open Hole ◽  
Critical Components ◽  
The Cost

As the cost of drilling and completion of offshore well is soaring, efforts are required for better well planning. Safety is to be given the highest priority over all other aspects of well planning. Among different element of drilling, well control is one of the most critical components for the safety of the operation, employees and the environment. Primary well control is ensured by keeping the hydrostatic pressure of the mud above the pore pressure across an open hole section. A loss of well control implies an influx of formation fluid into the wellbore which can culminate to a blowout if uncontrollable. Among the factors that contribute to a blowout are: stuck pipe, casing failure, swabbing, cementing, equipment failure and drilling into other well. Swabbing often occurs during tripping out of an open hole. In this study, investigations of the effects of tripping operation on primary well control are conducted. Failure scenarios of tripping operations in conventional overbalanced drilling and managed pressure drilling are studied using fault tree analysis. These scenarios are subsequently mapped into Bayesian Networks to overcome fault tree modelling limitations such s dependability assessment and common cause failure. The analysis of the BN models identified RCD failure, BHP reduction due to insufficient mud density and lost circulation, DAPC integrated control system, DAPC choke manifold, DAPC back pressure pump, and human error as critical elements in the loss of well control through tripping out operation.

Using Logging and Seismic Data to Identify Boundaries Between Different OWC Units in a Deepwater Carbonate Reservoirs

2021 ◽  
Author(s):  
Kangxu Ren ◽  
Junfeng Zhao ◽  
Jian Zhao ◽  
Xilong Sun
Keyword(s):  
Seismic Data ◽  
Carbonate Rocks ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Sedimentary Process ◽  
Core Samples ◽  
Tight Carbonate ◽  
Porosity And Permeability ◽  
Seismic Sections ◽  
Parameters Inversion

Abstract At least three very different oil-water contacts (OWC) encountered in the deepwater, huge anticline, pre-salt carbonate reservoirs of X oilfield, Santos Basin, Brazil. The boundaries identification between different OWC units was very important to help calculating the reserves in place, which was the core factor for the development campaign. Based on analysis of wells pressure interference testing data, and interpretation of tight intervals in boreholes, predicating the pre-salt distribution of igneous rocks, intrusion baked aureoles, the silicification and the high GR carbonate rocks, the viewpoint of boundaries developed between different OWC sub-units in the lower parts of this complex carbonate reservoirs had been better understood. Core samples, logging curves, including conventional logging and other special types such as NMR, UBI and ECS, as well as the multi-parameters inversion seismic data, were adopted to confirm the tight intervals in boreholes and to predicate the possible divided boundaries between wells. In the X oilfield, hundreds of meters pre-salt carbonate reservoir had been confirmed to be laterally connected, i.e., the connected intervals including almost the whole Barra Velha Formation and/or the main parts of the Itapema Formation. However, in the middle and/or the lower sections of pre-salt target layers, the situation changed because there developed many complicated tight bodies, which were formed by intrusive diabase dykes and/or sills and the tight carbonate rocks. Many pre-salt inner-layers diabases in X oilfield had very low porosity and permeability. The tight carbonate rocks mostly developed either during early sedimentary process or by latter intrusion metamorphism and/or silicification. Tight bodies were firstly identified in drilled wells with the help of core samples and logging curves. Then, the continuous boundary were discerned on inversion seismic sections marked by wells. This paper showed the idea of coupling the different OWC units in a deepwater pre-salt carbonate play with complicated tight bodies. With the marking of wells, spatial distributions of tight layers were successfully discerned and predicated on inversion seismic sections.

Wellhead Design Enables Offline Cementing and a Shift in Operational Efficiency

2021 ◽  
Vol 73 (05) ◽  
pp. 68-69
Author(s):  
Chris Carpenter
Keyword(s):  
Oil And Gas ◽  
Operational Efficiency ◽  
Asia Pacific ◽  
Significant Shift ◽  
Lost Circulation ◽  
Well Design ◽  
Geological Conditions ◽  
The Moment ◽  
Tubing Hanger ◽  
Column Pressure

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 202439, “Pushing Malaysia’s Drilling Industry Into a New Frontier: How a Distinctive Wellhead Design Enabled Implementation of a Fully Offline Well Cementing Resulting in a Significant Shift in Operational Efficiency,” by Fauzi Abbas and Azrynizam M. Nor, Vestigo, and Daryl Chang, Cameron, a Schlumberger Company, prepared for the 2020 SPE Asia Pacific Oil and Gas Conference and Exhibition, originally scheduled to be held in Perth, Australia, 20–22 October. The paper has not been peer reviewed. Traditionally, rigs are positioned over a well from the moment the surface casing is drilled until the installation of the wellhead tree. This results in the loss of precious time as the rig idles during online cementing. However, in mature Field A offshore Terengganu, Malaysia, a new approach eliminated such inefficiency dramatically. Operational Planning With oil production in Field A initiated in October 2015, historical data on well lithology, formation pressure, and potential issues during drilling were available and were studied to ensure that wells would not experience lost circulation. This preplanning is crucial to ensure that the offline cementing activity meets the operator’s barrier requirements. Petronas Procedures and Guidelines for Upstream Activities (PPGUA 4.0) was used for the development of five subject wells in Field A. In this standard, two well barriers are required during all well activities, including for suspended wells, to prevent uncontrolled outflow from the well to the external environment. For Field A, two barrier types, mechanical and fluid, allowed by PPGUA 4.0 were selected to complement the field’s geological conditions. As defined in PPGUA 4.0, the fluid barrier is the hydrostatic column pressure, which exceeds the flow zone pore pressure, while the mechanical barrier is an element that achieves sealing in the wellbore, such as plugs. The fluid barrier was used because the wells in Field A were not known to have circulation losses. For the development of Field A, the selected rig featured a light-duty crane to assist with equipment spotting on the platform. Once barriers and rig selection are finalized, planning out the drill sequence for rig skidding is imperative. Space required by drillers, cementers, and equipment are among the considerations that affect rig-skid sequence, as well as the necessity of increased manpower. Offline Cementing Equipment and Application In Field A, the casing program was 9⅝×7×3½ in. with a slimhole well design. The wellhead used was a monobore wellhead system with quick connectors. The standard 11-in. nominal wellhead design was used for the wells with no modifications required. All three sections of the casing program were offline cemented. They were the 9⅝-in. surface casing, 7-in. production casing, and 3½-in. tubing. The 9⅝-in. surface casing is threaded to the wellhead housing and was run and landed with the last casing joint. Subsequent wellhead 7-in. casing hangers and a 3½-in. tubing hanger then were run and landed into the compact housing.

About this title - Seismic Characterization of Carbonate Platforms and Reservoirs

10.1144/sp509 ◽  
2021 ◽  
Vol 509 (1) ◽  
pp. NP-NP
Author(s):  
J. Hendry ◽  
P. Burgess ◽  
D. Hunt ◽  
X. Janson ◽  
V. Zampetti
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Carbonate Platform ◽  
Carbonate Platforms ◽  
Oil And Gas Exploration ◽  
Seismic Modelling ◽  
Flow Units ◽  
Development Data ◽  
Seismic Characterization

Modern seismic data have become an essential toolkit for studying carbonate platforms and reservoirs in impressive detail. Whilst driven primarily by oil and gas exploration and development, data sharing and collaboration are delivering fundamental geological knowledge on carbonate systems, revealing platform geomorphologies and how their evolution on millennial time scales, as well as kilometric length scales, was forced by long-term eustatic, oceanographic or tectonic factors. Quantitative interrogation of modern seismic attributes in carbonate reservoirs permits flow units and barriers arising from depositional and diagenetic processes to be imaged and extrapolated between wells.This volume reviews the variety of carbonate platform and reservoir characteristics that can be interpreted from modern seismic data, illustrating the benefits of creative interaction between geophysical and carbonate geological experts at all stages of a seismic campaign. Papers cover carbonate exploration, including the uniquely challenging South Atlantic pre-salt reservoirs, seismic modelling of carbonates, and seismic indicators of fluid flow and diagenesis.

scholarly journals The structure of the sedimentary complex of the Middle and South Caspian depressions (Azerbaijan sector)

2021 ◽  
Vol 43 (4) ◽  
pp. 199-216
Author(s):  
N.P. Yusubov ◽  
I.S. Guliyev
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Sedimentary Cover ◽  
Clay Content ◽  
Geological Structure ◽  
Point Of View ◽  
South Caspian Basin ◽  
Origin And Evolution ◽  
Geological Interpretation ◽  
High Degree

The high degree of knowledge of the upper horizons of the sedimentary cover of the Middle and South Caspian depressions, given an insufficient increase in hydrocarbon reserves, leads to the need for a detailed approach to the search for oil and gas deposits in deep-seated sediments (over 6 km). During the geological interpretation of new highly informative seismic data, as well as data of deep drilling and petrological core studies, there were revealed obvious shortcomings in the concepts of the origin and evolution of the Middle and South Caspian depressions. These ideas misinterpret evolution, especially the South Caspian Basin, which is characterized by a number of unique features: very thick sedimentary cover (up to 22 km), extremely high sedimentation rate, low heat flow and reservoir temperatures, abnormally high pore and reservoir pressures, high clay content of the section, etc. The main purpose of the study was to elucidate the regional structure and features of the dissection of the sedimentary cover of the Middle and South Caspian depressions, the conditions of occurrence and distribution of facies and thicknesses of individual complexes of deposits. The paper analyzes the results of some previous studies of the geological structure of the Middle and South Caspian depressions based on the data of deep seismic sounding, seismological and gravimetric observations. We consider the main conclusions of these studies, about the geological structure of the sedimentary complex of the region’s, very outdated and subject to revision. The results of seismic stratigraphic analysis of seismic data allowed the authors to identify new data about the tectonic structure and express a completely different point of view regarding the structure of the sedimentary cover in the region. The work also touches on the issue associated with the tectonics of the region and the alleged subduction zone here.

scholarly journals On the issue of corrosion in the operation of oil and gas wells

2021 ◽  
Vol 225 ◽  
pp. 03006
Author(s):  
Svetlana Luibimova ◽  
Lilia Khuzina
Keyword(s):  
Oil And Gas ◽  
Poor Quality ◽  
Metal Corrosion ◽  
Gas Wells ◽  
Injection Wells ◽  
Factors Affecting ◽  
Lost Circulation ◽  
Oil And Gas Wells

The problem of leakage production strings in production and injection wells is becoming more and more urgent every year in Russia’s fields. As a result, the water encroachment of produced products increases, and as a result, the operation of wells becomes unprofitable. The main reasons for the leakage of wells are aging of well stock, poor quality cementation during final works during drilling, corrosion processes in places where aquifers come into contact with the string, killing of wells at pressures higher than the pressure of pressing, depressurization in coupling joints, metal corrosion and other technological reasons. Identification of factors affecting the deformation of production strings in the process of well corrosion is necessary and important, as it is taken into account in the development of measures to increase the accident-free operation of wells. 725 wells of PJSC TATNEFT were analyzed in this work. The analysis revealed that one of the reasons for the corrosion of production strings is the presence of lost circulation horizons, which confirms the analysis.

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