Pavlin Borissov Entchev

7980329, Jul 19, 2011

Jan 22, 2010

12/691783

Paul Matthew Spiecker - Manvel TX, US
Pavlin B. Entchev - Houston TX, US
Ramesh Gupta - Berkley Heights NJ, US
Richard Polizzotti - Milford NJ, US
Barbara Carstensen - Annandale NJ, US
Dennis G. Peiffer - Annandale NJ, US
Norman Pokutylowicz - Houston TX, US

ExxonMobil Upstream Research Company - Houston TX

E21B 21/01
E21B 21/06

175206, 175 66, 175207

A method and system for drilling a wellbore is described. The system includes a wellbore with a variable density drilling mud, drilling pipe, a bottom hole assembly disposed in the wellbore and a drilling mud processing unit in fluid communication with the wellbore. The variable density drilling mud has compressible particles and drilling fluid. The bottom hole assembly is coupled to the drilling pipe, while the drilling mud processing unit is configured to separate the compressible particles from the variable density drilling mud. The compressible particles in this embodiment may include compressible hollow objects filled with pressurized gas and configured to maintain the mud weight between the fracture pressure gradient and the pore pressure gradient. In addition, the system and method may also manage the use of compressible particles having different characteristics, such as size, during the drilling operations.

8469120, Jun 25, 2013

Apr 21, 2008

12/594314

Pavlin B. Entchev - Houston TX, US
John H. Jackson - Idaho Falls ID, US
John K. Montgomery - Houston TX, US

ExxonMobil Upstream Research Company - Houston TX

E21B 10/36

175393, 175 57, 175381, 175384

Drill bits are provided. The drill bits are of the fixed-cutter, rotary-type. The drill bits have a plurality of blades having cutting elements disposed therealong. Junk slots are formed between the respective blades. A knife opening is formed in at least two of the junk slots. Preferably, the knife openings are disposed substantially transverse to a longitudinal axis of the drill bit. The drill bit also has one or more ribbon cutters. The ribbon cutters cyclically protrude through knife openings in the junk slots in order to facilitate the fragmentation of cuttings ribbons moving through the junk slots during a drilling operation.

20070027036, Feb 1, 2007

May 25, 2006

11/441698

Richard Polizzotti - Milford NJ, US
Mehmet Ertas - Hillsborough NJ, US
Norman Pokutylowicz - Hillsborough NJ, US
Scott Milner - Somerville NJ, US
James Rigby - Kingwood TX, US
John Montgomery - Houston TX, US
Pavlin Entchev - Houston TX, US
Stuart Keller - Houston TX, US
Vishwas Gupta - Stafford TX, US
William Sisak - Houston TX, US

C09K 8/02

507143000

One embodiment of the invention is a variable density drilling mud comprising compressible particulate material in the drilling mud wherein the density of the drilling mud changes in response to pressure changes at depth. A second embodiment is a method for varying drilling mud density. The method comprises estimating the pore pressure and fracture gradient, and choosing a drilling mud with compressible materials wherein the effective mud weight of the drilling mud remains between the pore pressure and the fracture gradient in at least one interval of the wellbore. A third embodiment is an apparatus for drilling a wellbore.

20080060849, Mar 13, 2008

Jul 24, 2007

11/880688

Pavlin B. Entchev - Houston TX, US
Stuart R. Keller - Houston TX, US

E21B 7/24

175 56, 175 57, 29592

Methods and apparatus for mitigating the effects of vibration of various tools, such as those used downhole, by utilizing a vibration isolation device that incorporates Shape Memory Alloys (SMAs). For instance, in some embodiments, a vibration isolation device may be designed and deployed in a manner such that, when a vibration isolation device is operated in an expected manner, the force on the SMAs from static loading is sufficient to induce partial phase transformation between the austenite and martensite phases. This partial phase transformation may result in a reduced stiffness of the vibration isolation device in comparison to a tool in either a full austenite phase or full martensite phase.

20090050374, Feb 26, 2009

Feb 13, 2007

12/160999

Paul Matthew Spiecker - Manvel TX, US
Pavlin B. Entchev - Houston TX, US
Ramesh Gupta - Berkley Heights NJ, US
Richard Polizzotti - Milford NJ, US
Barbara Carstensen - Annandale NJ, US
Dennis G. Peiffer - Annandale NJ, US
Norman Pokutylowicz - Houston TX, US

E21B 21/06

175 66, 175207, 175 48, 175217, 175 65

A method and system for drilling a wellbore is described. The system includes a wellbore with a variable density drilling mud, drilling pipe, a bottom hole assembly disposed in the wellbore and a drilling mud processing unit in fluid communication with the wellbore. The variable density drilling mud has compressible particles and drilling fluid. The bottom hole assembly is coupled to the drilling pipe while the drilling mud processing unit is configured to separate the compressible particles from the variable density drilling mud. The compressible particles in this embodiment may include compressible hollow objects filled with pressurized gas an configured to maintain the mud weight between the fracture pressure gradient and the pore pressure gradient. In addition, the system and method may also manage the use of compressible particles having different characteristics, such as size, during the drilling operations.

20110265994, Nov 3, 2011

Jan 31, 2011

13/017832

Pavlin B. Entchev - Houston TX, US
Robert D. Kaminsky - Houston TX, US

E21B 43/14

166270

Systems and methods for creating a hydraulic barrier at an interface between high and low permeability regions that may exist in high permeability-contrast subterranean formations. These systems and methods may include providing injection and/or production wells that are completed within the high and/or low permeability regions, supplying a pore throat blocking agent to an interface between the high and low permeability regions, and forming the hydraulic barrier at the interface. The pore throat blocking agent may be sized to substantially flow through the high permeability region while being substantially blocked, or occluded, from the low permeability region. In some embodiments, the hydraulic barrier may be greater than one acre (0.4 hectare) in area. In some embodiments, the subterranean formation may include an oil reservoir. In some embodiments, the high and/or low permeability formations may be swept concurrently and/or independently to remove oil from the oil reservoir.

20120125631, May 24, 2012

Apr 13, 2010

13/264948

Pavlin B. Entchev - Houston TX, US
William A. Sorem - Katy TX, US
Zhihua Wang - Stavanger, NO
David A. Baker - Bellaire TX, US
John K. Montgomery - Houston TX, US
Larry Mercer - Doha, QA
Dennis H. Petrie - Sugar Land TX, US

RASGAS COMPANY LIMITED - Doha
EXXONMOBIL UPSTREAM RESEARCH COMPANY - Houston TX

E21B 29/00
B23P 17/00
E21B 33/12

166376, 166192, 166386, 29416

A bridge plug arrangement includes a plug having an upper end and a bottom end. The bridge plug arrangement also optionally includes a cylindrical seat. The bridge plug arrangement further includes a tubular member. The tubular member may be part of a casing string. The tubular member is configured to receive the plug and, when used, the seat. The plug and/or the seat may be fabricated from a frangible material. A method for diverting fluids in a wellbore using the bridge plug arrangement is also provided. The method may include landing the plug onto the seat within the wellbore below a subsurface zone of interest. Treatment fluids are then injected into the wellbore, where they are diverted through perforations and into a formation. The plug and/or seat is then optionally broken into a plurality of pieces through use of a downward mechanical force.

20130062055, Mar 14, 2013

May 26, 2011

13/697769

Randy C. Tolman - Spring TX, US
Pavlin B. Entchev - Houston TX, US
Renzo M. Angeles Boza - Houston TX, US
Dennis H. Petrie - Sugar Land TX, US
Kevin H. Searles - Kingwood TX, US
Abdel Wadood M. El-Rabaa - Plano TX, US

E21B 41/00
E21B 43/116
E21B 43/119
E21B 47/09

16625001, 166 53, 175 451

Autonomous units and methods for downhole, multi-zone perforation and fracture stimulation for hydrocarbon production. The autonomous unit may be a perforating gun assembly, a bridge plug assembly, or fracturing plug assembly. The autonomous units are dimensioned and arranged to be deployed within a wellbore without an electric wireline. The autonomous units may be fabricated from a friable material so as to self-destruct upon receiving a signal. The autonomous units include a position locator for sensing the presence of objects along the wellbore and generating depth signals in response. The autonomous units also include an on-board controller for processing the depth signals and for activating an actuatable tool at a zone of interest.