Exxonmobil Upstream Research Company

Kaustubh S Kulkarni

Sai S Rao

Timothy J Nedwed

Andrey A Troshko

Douglas A Mitchell

Rachna Jain

Brian J O'Donnell

Bill R Meeks

Gregory King

Methods of mitigating lost circulation while drilling a wellbore. The methods include circulating a drilling mud to a downhole end of the wellbore via a drill string and, during the circulating, drilling the wellbore with a drill bit of the drill string. The methods also include detecting lost circulation within the wellbore while drilling the wellbore and include providing a monomer solution to the wellbore. The methods further include providing a catalyst to the wellbore responsive to detecting the lost circulation event and combining the monomer solution and the catalyst to polymerize a monomer from the monomer solution, within the wellbore, and forming a viscous plug within the wellbore. Subsequent to the combining, the methods include flowing at least a portion of the viscous plug within the wellbore and into a zone of lost circulation that extends within a subsurface region. The methods further include at least partially occluding fluid flow from the wellbore and into the zone of lost circulation with the viscous plug.

Methods of mitigating lost circulation while drilling a wellbore

System and methods for cleaning debris or particulates from a wellbore using foam is provided, including predicting if a foam cleanout of a well is feasible by calculating foam properties at each of a number of segments in a well during a foam cleanout, comparing the foam properties to screening limits, providing an output to indicate if a foam cleanout is feasible. If feasible, the foam cleanout is performed.

Foam cleanout methods and systems for wellbores

A method for conducting a wellbore operation includes drilling a wellbore through one or more hydrocarbon bearing subterranean formations with a drill bit arranged at an end of a drill string, wherein an annulus is defined between the drill string and an inner wall of the wellbore. A foam is generated with a foam generator of an annular injection system in communication with the annulus, and the foam is introduced into the annulus with the annular injection system.

Foam cap drilling methods

Methods for enhancing transport rate of particles of size Din a cuttings bed within an annulus of a wellbore during drilling operations. One method comprises estimating, with a computer, a current particle size distribution (PSD) of a particle bed including particles of size Dwithin a measured depth (MD) range of the wellbore; calculating, with the computer, a target PSD of the MD range using a using a one-dimensional transient model incorporating a particle transport model; determining, with the computer, a pumping PSD to achieve the target PSD within the MD range; and adding the pumping PSD to a drilling fluid flowing within the annulus, thereby enhancing the transport rate of particles of size Dwithin the MD range. The particle transport model may be a surface-based transport model.

Methods for enhancing cuttings transport and hole cleaning in oil and gas wells

Designing a drillstring in for use in a wellbore, such as a deviated or horizontal wellbore, particularly with application to extended reach wellbores. Method comprises determining the downhole weight-on-bit transmitted by a drillstring by determining a baseline tension profile and baseline torque profile in a drill string rotating off-bottom, and then using such profiles in conjunction with a selected surface weight-on-bit slack-off value to calculate a drillstring tension profile and rotating torque profile with the bit on bottom and having weight applied thereto. The method includes buckling limit checks and rig operational limit checks to determine if sufficient torque and DWOB can be transmitted through the drillstring, and to determine whether the drill string remains operable even though portions thereof may be in a buckled condition.

Growing community of inventors

The Woodlands, TX, United States of America

Kaustubh S Kulkarni