Patents that are close to my invention or abandoned or expired, can I still be granted a patent for my invention?

For purposes of determining patentability, expired and "abandoned" patents are relevant. Whether the patents are relevant includes the question of whether those patents make your invention obvious.

The short answer is: "it depends". To obtain a patent for your invention, your invention must be useful, novel and non-obvious compared to what other have done in the past. The enforce-ability of the patents found in the patent search you commissioned has no role in your ability to obtain your patent. The enforce-ability of those patents is, however, critical as to whether they can enforce their patents against you if you practice your invention. So, a patent attorney can give you a patent-ability opinion based on a comprehensive description of your invention as compared to the patents found in your commissioned search. You should also be aware that no patent-ability search is 100% conclusive of all possible prior art that might be relevant to the patent ability of your invention. There are many reasons for this. One is that patent applications are kept secret for 18 months after filing and even longer if a non publication request is filed. So, there is an 18 month window in which you cannot find the prior art to your invention because you have no public access to it. Another reason is that any enabling disclosure or actual prototype might be relevant prior art. These types of prior art are generally hard to find, unlike patent databases. Even if you obtain a patent for your invention, your patent can be subsequently invalidated based on prior art that the patent examiner was not aware of. Such prior art might turn up in a more exhaustive validity search which might cost more than the entire cost to obtain a patent. This happens quite frequently in the context of patent infringement litigation. Additionally, there are other old and new administrative proceedings in the Patent Office that can be used by potential infringes to challenge the validity of a patent based on prior art that was not put in front of the examiner who allowed your patent.

That does not matter. If they are prior art then they may teach or disclose what your invention is. In that case you can't receive a patent. Remember a patent is awarded to the first person to put that novel invention out there. If someone invented it before you it does not matter if they abandoned it after they filed an application. The invention is out there for all to see and it is too late for you to file a patent on the same thing. But i would recommend that unless you are an experienced patent attorney or patent agent i would not try to guess if these 15 pieces of prior art prevented you from filing a patent on your invention. Seek professional advice.

Whether a patent is abandoned or expired does not change how it can be used against you if you file for a patent. What matters is how closely the patent describes your idea.

You now have the "prior art" - patents and published applications that were filed before your invention. For you to obtain a patent on your invention - it must be (1) new (different from the prior art), (2) useful (like the prior art) and (3) unobvious (more than simply different from the prior art - typically something "unexpected").