RESEARCH PAPERS
Geolog is an active contributor to the technological advances in the mud logging field. This is achieved through its strong focus on R&D as well as its ongoing work with its clients, with whom it often works in conjunction to design, develop and evaluate new surface logging technologies.
Below are some of the research papers Geolog has written with its clients over the years:
1. Advanced Surface Logging technologies provide solutions for deepwater drilling and formation evaluation.
Paper presented at the Deep Offshore Technology Conference, Amsterdam, December 2010
2. How To Improve Drilling Efficiency Using The Cutting Weighting Technology
ENI/Geolog research paper presented at the 2005 OMC fair.
3. Real-Time Wellbore Stability Analysis at the Rig-Site (SPE 37670)
ENI Research paper presented at SPE/IADC Drilling Conference, 4-6 March 1997, Amsterdam, Netherlands
The resource was carried out in collaboration with GEOLOG
4. Characterization of Conductive Fractures While Drilling (SPE 38177)
GEOLOG Research paper presented on formation fracture modelling obtained via accurate advanced mud flow measurements while drilling
5. Surface logging for fractured reservoirs
SPE ATW: Fractured Reservoirs Development: Challenges and Opportunities - 1st-3rd February, 2010
1. Advanced Surface Logging technologies provide solutions for deepwater drilling and formation evaluation.
Paper presented at the Deep Offshore Technology Conference, Amsterdam, December 2010
2. How To Improve Drilling Efficiency Using The Cutting Weighting Technology
ENI/Geolog research paper presented at the 2005 OMC fair.
3. Real-Time Wellbore Stability Analysis at the Rig-Site (SPE 37670)
ENI Research paper presented at SPE/IADC Drilling Conference, 4-6 March 1997, Amsterdam, Netherlands
The resource was carried out in collaboration with GEOLOG
4. Characterization of Conductive Fractures While Drilling (SPE 38177)
GEOLOG Research paper presented on formation fracture modelling obtained via accurate advanced mud flow measurements while drilling
5. Surface logging for fractured reservoirs
SPE ATW: Fractured Reservoirs Development: Challenges and Opportunities - 1st-3rd February, 2010
1. Advanced Surface Logging technologies provide solutions for deepwater drilling and formation evaluation.
Paper presented at the Deep Offshore Technology Conference, Amsterdam, December 2010
As the oilfield progresses towards deeper waters and more challenging drilling operations, it faces two series of critical issues, related respectively to formation evaluation and drilling optimization.
Formation Evaluation:
On deepwater operations, Formation Evaluation based on gas analysis requires dedicated solutions: mainly because a long riser means that the mud is reaching the surface at very low temperatures. , Gas extraction from cold mud, and consequent analysis, are difficult.
Drilling Optimization:
Due to the costs and criticalities involved in operating in deepwater conditions two factors become paramount:
First, it becomes critical to be able to optimize well conditions.
Second, it is crucial to react quickly in case the pressures balance of the well changes.
In recent years, Surface Logging services have supported increasingly complex deep offshore operations. In doing so, solutions have been found for deepwater exploration enabling to maximize the data obtained from the well and to react promptly to drilling problems.
This paper presents an array of Advanced Surface Logging solutions for Deepwater operations, which is constituted of the following:
- Advanced gas extraction system designed for deepwater conditions based on a constant volume degasser, a mud heater, and a real time data quality control system. A case history is presented highlighting the critical advantages of the system.
- A system to accurately evaluate the volume of cuttings being drilled, providing information on the hole stability and on the effectiveness of the hole cleaning. Also in this case a series of recent case histories is presented.
- Accurate and advanced flow measurement systems, utilized to spot mud imbalances as early as possible and in the same time to provide real time interpretation of the type of fractures encountered.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.comENI/Geolog research paper presented at the 2005 OMC fair.
Field Results following two years of joint field work between Geolog and the Italian Oil & Gas major ENI SpA.
To solve the serious problems experienced drilling deviated wells, ENI started experimenting with Geolog’s cutting weight sensors in 2003 (later to be named GeoCVM). One such device is installed in front of each shale shaker, and connected to the mud logging data acquisition system. Geolog’s real time engineering software transforms the weight of cuttings measured at the shale shakers into volume and the results are graphically displayed on the rig floor. Extensive field results confirm that the cutting weight sensors provide an accurate real time detection of cuttings volume taken out from the hole. This information correctly analyzed together with other drilling data, can be extremely useful to understand the different phenomena occurring while drilling. In particular the cuttings machine data are evaluated both versus depth and versus time in order to obtain the instantaneous picture of wellbore behaviour during drilling, tripping and circulating.
As a result, the drilling crew knows exactly what is happening downhole, e.g. when caving occurs or when cuttings remain in the hole and additional circulation is required. Furthermore, additional information is provided to the fluid engineer to better evaluate the mud efficiency.
The paper concludes that an accurate real time measurement of cuttings flow is essential to correctly evaluate the borehole behaviour while drilling, in combination with geomechanical borehole stability analysis and all other available drilling information and data.
A thorough, reliable, understanding of what is “really” happening downhole during drilling, tripping, allows the most appropriate operational decisions to be made, to:
- optimise drilling efficiency
- prevent getting stuck
- modify RIH and or POH procedures
- improve cementation when electrical logging caliper is not available to estimate cement volume.
- modify mud program and measure the effectiveness of the change.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com
Problems related to wellbore instabilities are a well known source of additional costs. According to published data they may amount up to 15% of the total drilling budget of a well. The development of an efficient industrial methodology to solve these problems is therefore compulsory for any operator.
To be successful, this methodology has to include three fundamental steps:
- diagnosis of the mechanism at the origin of the problems; - determination of the main parameters governing the mechanism; - modeling of the problem in order to properly size its cure.
To be efficient, all three steps should be performed not only during the planning phase but also in real time, directly at the rig-site during drilling.
The paper will present the wellbore stability package developed by Agip and will put special emphasis on its real time dimension at the rig site. Several field cases in a critical area of Southern Italy will be used to illustrate it. The methodology is based upon three main moments which will be described in detail:
- careful monitoring of the instabilities signals - e.g. tripping conditions, cavings formation, physico-mechanical characterization of the cavings, detection of ageing in mud, etc...:
- formation evaluation by means of measurements on cuttings to determine their main properties - e.g. strength, stiffness, permeability, etc.;
- quantification of the problem with a series of desktop based computer models - e.g. linear elastic, elasto plastic, coupled thermo-poro-mechanic, etc.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com3. How To Improve Drilling Efficiency Using The Cutting Weighting Technology (SPE 37670)
ENI Research paper presented at SPE/IADC Drilling Conference, 4-6 March 1997, Amsterdam, Netherlands
The resource was carried out in collaboration with GEOLOGENI Research paper presented at SPE/IADC Drilling Conference, 4-6 March 1997, Amsterdam, Netherlands
Problems related to wellbore instabilities are a well known source of additional costs. According to published data they may amount up to 15% of the total drilling budget of a well. The development of an efficient industrial methodology to solve these problems is therefore compulsory for any operator.
To be successful, this methodology has to include three fundamental steps:
- diagnosis of the mechanism at the origin of the problems; - determination of the main parameters governing the mechanism; - modeling of the problem in order to properly size its cure.
To be efficient, all three steps should be performed not only during the planning phase but also in real time, directly at the rig-site during drilling.
The paper will present the wellbore stability package developed by Agip and will put special emphasis on its real time dimension at the rig site. Several field cases in a critical area of Southern Italy will be used to illustrate it. The methodology is based upon three main moments which will be described in detail:
- careful monitoring of the instabilities signals - e.g. tripping conditions, cavings formation, physico-mechanical characterization of the cavings, detection of ageing in mud, etc...:
- formation evaluation by means of measurements on cuttings to determine their main properties - e.g. strength, stiffness, permeability, etc.;
- quantification of the problem with a series of desktop based computer models - e.g. linear elastic, elasto plastic, coupled thermo-poro-mechanic, etc.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com4. Characterization of Conductive Fractures While Drilling (SPE 38177)
GEOLOG Research paper presented on formation fracture modelling obtained via accurate advanced mud flow measurements while drilling
When dealing with naturally fractured formations, the knowledge of the location and the permeability of the fractures intersecting the wellbore has a strong technical and economical impact upon drilling, production and reservoir management strategies.
This paper presents a methodology which allows to perform a real time characterization of the conductive fractures intercepted by the bit while drilling. Such fractures are detected by monitoring continuously the mud losses at the rig-site using flow-meters measuring both the ingoing and the outgoing mud flow. The accuracy of such measurements is very high (mud losses as small as 20 liters can be monitored), and therefore also the smallest conductive fractures can be
pinpointed.
A simple analytical model describing the mud invasion into a single fracture is used to invert the mud loss data in order to estimate the aperture and permeability of each fracture. This model has been validated with core measurements, and it is used in real time to perform a quick but sufficiently precise analysis.
The application of this technique to several field cases is also illustrated and discussed in terms of:
1. interpretation of the process of fracture plugging;
2. real time evaluation of the hydraulic aperture of the conductive fractures;
3. generation of a “secondary permeability log”.
Moreover some operative implications are discussed, such as:
1. in the field of drilling, the muds, the lost circulation materials (LCM) and the cement plugs can be selected properly in order to avoid massive circulation losses and to minimize the damage due to mud invasion;
2. in the field of production engineering, the completion schemes and the stimulation operations can be optimized through the knowledge of the most conductive intervals;
3. in the field of reservoir engineering, a better modeling can be performed and a better exploitation of the naturally fractured reservoirs can be achieved.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com
Application of advanced surface logging techniques is a cost-effective means of getting real-time formation evaluation – particularly important in a fractured reservoir. In particular:
High resolution flow measurement while drilling can identify presence of open fractures.
High quality, repeatable gas detection can be achieved applying a series of interconnected
techniques, practices and technologies.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com
GEOLOG Research paper presented on formation fracture modelling obtained via accurate advanced mud flow measurements while drilling
When dealing with naturally fractured formations, the knowledge of the location and the permeability of the fractures intersecting the wellbore has a strong technical and economical impact upon drilling, production and reservoir management strategies.
This paper presents a methodology which allows to perform a real time characterization of the conductive fractures intercepted by the bit while drilling. Such fractures are detected by monitoring continuously the mud losses at the rig-site using flow-meters measuring both the ingoing and the outgoing mud flow. The accuracy of such measurements is very high (mud losses as small as 20 liters can be monitored), and therefore also the smallest conductive fractures can be
pinpointed.
A simple analytical model describing the mud invasion into a single fracture is used to invert the mud loss data in order to estimate the aperture and permeability of each fracture. This model has been validated with core measurements, and it is used in real time to perform a quick but sufficiently precise analysis.
The application of this technique to several field cases is also illustrated and discussed in terms of:
1. interpretation of the process of fracture plugging;
2. real time evaluation of the hydraulic aperture of the conductive fractures;
3. generation of a “secondary permeability log”.
Moreover some operative implications are discussed, such as:
1. in the field of drilling, the muds, the lost circulation materials (LCM) and the cement plugs can be selected properly in order to avoid massive circulation losses and to minimize the damage due to mud invasion;
2. in the field of production engineering, the completion schemes and the stimulation operations can be optimized through the knowledge of the most conductive intervals;
3. in the field of reservoir engineering, a better modeling can be performed and a better exploitation of the naturally fractured reservoirs can be achieved.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com5. Surface logging for fractured reservoirs
SPE ATW: Fractured Reservoirs Development: Challenges and Opportunities - 1st-3rd February, 2010
SPE ATW: Fractured Reservoirs Development: Challenges and Opportunities - 1st-3rd February, 2010
Application of advanced surface logging techniques is a cost-effective means of getting real-time formation evaluation – particularly important in a fractured reservoir. In particular:
High resolution flow measurement while drilling can identify presence of open fractures.
High quality, repeatable gas detection can be achieved applying a series of interconnected
techniques, practices and technologies.
Clients who wish to download the full research paper should request access by email to technology@geologinternational.com